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An Introduction To DApps & Blockchain Technology - YouTube
Channel: Tech With Tim
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hello everybody and welcome to another
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youtube video so in today's video i'm
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going to be talking about blockchain
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technology and d apps otherwise known as
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decentralized applications now i want
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this video to act as a high level
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introduction to decentralized
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applications and how you can use
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blockchain technology to actually create
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apps now the reason i'm making this is
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because recently there's been a lot of
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hype around cryptocurrency but a lot of
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people look at cryptocurrency and
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blockchain in general and think that's
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only a way to make money they treat it
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simply as an investment and something
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that they can trade almost like a stock
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however there's a completely different
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side of cryptocurrency which is the
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development side well that's what this
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video is going to focus on so in this
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video i'm going to talk to you about
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what a blockchain is what
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decentralization is what a d app is and
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then the pros and cons of a d-app and
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some of the different solutions that
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companies are implementing to create
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d-apps however before we go any further
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i do need to mention that i myself am
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not a cryptocurrency or blockchain
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expert and that's why for this video i
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teamed up with a company called cartesi
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which helped me shape a lot of the
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content in this video now cartesia is a
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company that's dedicated to making the
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blockchain and cryptocurrency more
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accessible to developers like you and i
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they have a ton of different products
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and solutions that allow the blockchain
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to be more affordable to use easier to
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use and they just provide a bunch of
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tutorials resources and really cool
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products and you can check them out from
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the link in the description now they
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also are the sponsor of this video i'll
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likely be working with them in the
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future to create in-depth tutorials on
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how to actually make decentralized
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applications but as i said in this video
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it's just going to be a high level
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overview on how d apps work so let's go
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ahead and get started
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[Music]
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so before we get into decentralized
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applications the first thing you need to
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understand is what a blockchain is so
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i'll give you a simple definition here a
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blockchain is a system of storing
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information that makes it extremely
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difficult or impossible to hack cheat or
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change so generally speaking we can
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trust this system and we know everything
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on a blockchain is true accurate and
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complete information and it's not been
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hacked or kind of modified maliciously
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in any way now going a bit further
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blockchains are used in cryptocurrencies
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like ethereum bitcoin and many other
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cryptocurrencies that you would know and
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the way they work is they're a digital
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ledger of all of the transactions that
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have occurred in this cryptocurrency's
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history now this ledger is distributed
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to all of the different computers that
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are sitting on the blockchain network so
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you may have heard of the term miners
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before these are really computers that
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are sitting on the blockchain and they
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store a copy of this digital ledger so
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every single computer that's on for
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example the ethereum network has a copy
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of the ethereum blockchain and this
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makes it very very hard for someone to
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actually maliciously change or send a
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malicious transaction on the blockchain
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now the way that works is if someone
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wanted to actually send something
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through on the blockchain that was
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inaccurate was false was some malicious
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type of transaction or they wanted to
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modify some block or something they
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would need to actually do that on almost
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all of the computers that are on the
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blockchain because every blockchain is
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storing or sorry every computer is
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storing a copy of the blockchain so if
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you were to send through a malicious
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transaction it'd be very easy to detect
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because all of these other computers on
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the blockchain would say hey i don't
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have that transaction here that's not
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accurate we're not going to include that
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on the blockchain get rid of it now
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obviously i'm oversimplifying here but
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that's really the basics of how a
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blockchain works and that's why we call
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it decentralized because it's a
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distributed ledger across all of the
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computers on the network on the
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blockchain network and that means we can
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trust that everything on the blockchain
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is correct because there's not one
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centralized organization entity power
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government whatever controlling what
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goes on the blockchain it's a peer right
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or it's a group of computers all around
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the world sitting on the blockchain
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network so to end off this section i'll
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just say that the complete opposite of
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something like a blockchain would be
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something like a bank right a bank also
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has a ledger of transactions it keeps
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the balances of different accounts that
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are with that bank however this is all
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controlled by a central organization
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there's not a large group or a large
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network of computers or random people
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around the world controlling this it's
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one central institution and maybe this
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institution is backed by a government or
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something like that but that means you
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cannot be guaranteed that there won't be
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any malicious activity or stuff going on
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with the transactions occurring because
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there's only one entity controlling this
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it is centralized not decentralized so
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before moving forward i just want to
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quickly talk to you about some of the
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main advantages of decentralization
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now really the core advantage is you
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never have to worry about trust you
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never have to put your trust in a
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central organization institution
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government whatever it may be and that
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is really just a great thing because you
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know the famous saying goes absolute
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power corrupts absolutely and we can
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look in history and see lots of examples
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where a large institutional organization
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has been corrupted has been malicious
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and wasn't actually able to be trusted
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and you can go and look at a lot of
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other countries and see what they've
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done with their currency mass inflation
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stealing from the people go on you can
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find all kinds of examples but that's
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really the core advantage of
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decentralization is there's no need to
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trust i don't have to put my trust in
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you you don't have to put your trust in
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me we trust the entire network as a
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whole because it's next to impossible
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for any central entity organization to
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go in there and be malicious and do
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something fraudulent that is the
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advantage of decentralization and that's
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really the whole reason why
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cryptocurrency has become super popular
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especially in a lot of parts in the
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world where they cannot trust their
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government or cannot trust a banking
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organization or maybe don't even have
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access to that so finally we can start
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talking about d apps otherwise known as
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decentralized applications now d apps
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are really just decentralized apps
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that's all they are that means they use
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some type of blockchain technology and
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we can trust all of the code associated
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with this application because it's
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completely open source it never has any
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downtime and once it's added to the
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network it cannot be removed modified or
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changed so just like transactions we
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know we can trust when they're on the
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blockchain we know we can trust all of
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the code that's on the blockchain
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because we can see it ourself we know it
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cannot be changed or modified and we
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know it's never just going to disappear
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because the blockchain is always
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available the blockchain never goes down
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i won't explain that too much more but
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that's pretty much how it works now what
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is a smart contract well a smart
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contract as i was kind of alluding to is
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just code sitting on the blockchain it
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can be executed by the blockchain and
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you can think of it kind of like a set
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of rules the most basic example of a
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smart contract is something that allows
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you to exchange one coin for another so
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the best analogy that i've actually
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found for a smart contract is something
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like a vending machine so a vending
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machine stores money and it stores you
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know some type of goods right in this
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case maybe we'll say it stores chips or
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food or whatever if you give the correct
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amount of money to the vending machine
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you always get the good that you are
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looking for if you give too much money
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it gives you change no matter what it
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always works a smart contract is exactly
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the same way just like you might have
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your own ethereum wallet you can
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actually have ethereum stored in your
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smart contract or maybe some other type
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of good or service or coin or whatever
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it may be and every time you give
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certain input to this smart contract you
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always get the same output it can never
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be changed it's not malicious you can't
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go in and modify it or hack it and that
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is how we can trust applications that
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are on the blockchain because they are
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decentralized they work just like when i
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send you a coin on the blockchain so
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hopefully that's a decent enough
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explanation but you use smart contracts
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to add executable code to the blockchain
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and then that code is used by an
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application 8d app and that is why you
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know you can trust the application that
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you're using because it's distributed on
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the blockchain so what i just said
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sounds great and you're probably
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wondering why everyone doesn't just go
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use decentralized applications or
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actually make decentralized applications
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but the reason why is because there's a
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lot of disadvantages as well now the
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largest disadvantage with decentralized
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applications is the cost it just costs
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you a lot of money a lot of
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cryptocurrency to actually be able to
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run a decentralized application
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not only do you need to upload the smart
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contract to the blockchain that costs
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you money and transaction fees then you
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also need to use the smart contract make
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calls on the smart contract which costs
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you transaction fees and then if you
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want to store any information on the
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blockchain that's going to cost you
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money and it just is very very expensive
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even storing very small amounts of data
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on the blockchain can cost you literally
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hundreds if not thousands of dollars and
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well it doesn't make sense for a lot of
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companies or applications to use this
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because of the extremely high fees now
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some of the other main disadvantages of
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decentralized applications include the
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high latency it can take a lot of time
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to send transactions or upload new smart
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contracts poor user experience inability
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to manage a ton of private keys and
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wallets and all the other data that you
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need right now it's just not the best
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experience for developers fortunately
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though the sponsor of this video which
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is cartesi is trying to help that they
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have a bunch of different solutions you
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can check them out from the link in the
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description to lower the cost associated
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with creating decentralized applications
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and remove a lot of those headaches but
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still there's a lot of disadvantages
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even using some of these great solutions
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provided by companies like cartesi so as
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i was saying there is a lot of
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disadvantages and problems with
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decentralized applications however there
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is different types of solutions that can
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be implemented to make them more cost
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efficient and to make them have a lower
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latency now those solutions are
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categorized into layer 1 solutions and
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layer 2 solutions now layer 1 solutions
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use the underlying block chain
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technology so a layer 1 solution would
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be just using ethereum or using bitcoin
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using the actual cryptocurrency or
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blockchain itself now one solution
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within the layer one solutions is
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something called sharding now what
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sharding is is kind of splitting up all
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of the code or all of the you know
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aspects of a decentralized application
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into things called shards and then
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distributing that on the blockchain
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network such that it gets executed
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faster and you don't need to wait for
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say an entire massive large piece of
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code to be executed instead you have you
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know 20 or 30 pieces of code that are
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being executed or 20 or 30 shards that
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need to be you know run through the
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network and so you can kind of split
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this up and things can go a lot faster
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just like what would happen if you say
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split your application into multiple
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threads or multiple cores so that's one
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solution layer one solution called
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sharding that can kind of increase the
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speed and cost effectiveness sorry of
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using blockchain however then you have
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layer two solutions now layer 2
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solutions are typically more advanced
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and what they are is actually a
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technology or system that lies above the
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underlying block chain technology so an
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example of a layer 2 solution would be
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something like a state channel now a
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state channel is pretty complicated to
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explain but really it's a way that two
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users can communicate without using the
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blockchain in the way in which the
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blockchain would work a little bit
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confusing but it's like using the
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blockchain just not using the blockchain
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such that you don't have to pay the huge
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latency and cost associated with the
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blockchain so what happens is two users
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will communicate with each other using
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this state channel and then once the
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communication is done or the transaction
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is complete only then will it be
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uploaded to the blockchain so rather
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than say having a thousand
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microtransactions occurring on the
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blockchain you have those occur in the
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state channel and then those get wrapped
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into one larger transaction which then
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gets uploaded onto the blockchain
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again the purpose of that is to lower
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the latency and to make sure that you're
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not going to have to pay massive fees
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for all of the different transactions
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that are going through now in this video
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i'm not going to explain exactly how
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these solutions work i'm just trying to
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give you an idea of what's kind of going
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on out there and how people are trying
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to mitigate the disadvantages of the
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blockchain so these solutions as i
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stated them do still make sure that the
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trust is secure they use very advanced
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math and cryptography to make sure that
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everything is all good but those are
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just two examples of a layer one and a
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layer two solution and how you can kind
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of mitigate some of those disadvantages
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of the blockchain so i'm gonna start
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wrapping up the video here by just
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giving you two examples of decentralized
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applications so that you can kind of
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read about them and check them out for
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yourself so the first application is
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something called the uniswap now uniswap
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is a decentralized finance protocol so
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it's called d5 and this allows you to
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actually exchange cryptocurrencies for
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each other so this is a d app you can
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look up uniswap and kind of see how it
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works if you want to learn more about it
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but another more interesting one that
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was actually developed by cartesi using
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some of their solutions is called
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haudelum poker so hodl hodl is kind of
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the term in cryptocurrency for holding
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your coins no matter what never selling
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them so it's kind of a punny name in
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that sense but this is an implementation
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of poker texas hold'em in which it's
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actually decentralized so you don't have
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to worry about trusting some large poker
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organization or website there's actually
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a lot of history of poker websites and
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poker players specifically cheating and
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scamming other people in this case you
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just trust the blockchain and this
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allows you to play poker without
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worrying about you know being scammed or
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fraud or people seeing your cards or
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mixing up the shuffle whatever it may be
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so i'll leave a link to that game in the
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description there's a great video by
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cartesi that explains kind of how that
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works that you can check out but i think
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with that i'm going to end the video
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here so as i mentioned i did team up
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with cartesi to create this video they
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helped me come up with a lot of the
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content that i shared here they're the
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true blockchain and cryptocurrency
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experts well you should check them out
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from the link in the description they
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provide a lot of layer one and layer two
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solutions to help create d apps
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decentralized applications and really
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mitigate some of those disadvantages
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that i talked about before look for some
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more videos coming from them in the
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future related to actually creating d
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apps and let me know what you thought of
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this video in the comments down below
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with that said like the video if you
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enjoyed subscribe to the channel and i
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will see you in another one
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[Music]
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you
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