IOTA's Tangle - Simply Explained - YouTube

Channel: Simply Explained

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When Bitcoin was first released to the world in 2008 it started a revolution.
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People claimed that the blockchain would solve many problems and that it has countless of
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applications.
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Blockchains indeed have very interesting properties and you can learn all about them in this video
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here.
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However they have one big limitation and that is that don’t scale very well.
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This is exactly the problem that the creators of IOTA wanted to solve.
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Instead of using a blockchain, IOTA uses something called a DAG or tangle.
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DAG is short for Directed Acyclic Graph and it’s a storage system where individual items
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link to each other.
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“Directed” means that the link between items always have a direction and acyclic
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means that you cannot create loops inside this structure.
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This might sound complicated, so let’s take a look at a simple tangle.
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Each square represents a single transaction and is also called a “site”.
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Each site contains all the details about the transaction: such as the sender, the receiver
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and the amount of coins.
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It also has a connection to at least two other transactions.
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These are called “edges” and they validate the transactions.
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Here is an example of a bigger Tangle.
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Near the end of our Tangle we find a few transactions that don’t have two or more incoming edges.
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This means that these transactions are unconfirmed.
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We also call these the tips of the tangle.
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Alright now that we understand some of the IOTA terminology, let’s take a look at how
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we can add a new transaction to the tangle.
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We have to attach our new transaction to one of the tips of the tangle.
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An algorithm selects two of them at random and makes sure that the transactions don’t
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conflict with one another.
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If one of the tips is a fake transaction, it is ignored and a new tip is selected.
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If everything checks out, we attach our transaction to the two tips.
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This adds our transaction to the tangle and verifies the two other transactions.
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Our transaction is now part of the tangle and becomes a new tip.
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This technique makes IOTA’s tangle incredibly scalable.
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For every transaction that is added to the tangle, two others are being confirmed.
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This means that the network doesn’t slow down when there are a lot of new transactions.
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In fact, it actually speeds up!
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That’s all great, but how do we know we can trust a transaction?
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In traditional blockchains people often use the number of confirmations to check wether
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or not a block should be trusted.
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Well IOTA has similar technique.
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Each site has a weight.
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This number signifies the amount of work that a node has done to make this transaction.
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In other words: a higher number means the node spent more time doing the proof-of-work
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for that transaction.
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Each transaction also has a cumulative weight.
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This is the sum of it’s own weight plus the sum of the weights of all transactions
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that approve this transaction.
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It seems quite complicated, but it really isn’t.
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Here is an example of a Tangle where every transaction has a weight of 1.
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We’ll put the weight of an individual transaction in the bottom right of each square.
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Now let’s check how trustworthy this pink transaction is by calculating its cumulative
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weight.
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To do that, we sum up the weight of the two transactions that have approved it.
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But those transactions where approved by other transaction as well.
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So we keep summing up all these weights until we get to the end of the tangle.
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In this case, the accumulative weight of the site is 6.
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Transactions with a high cumulative weight are usually older and have more direct or
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indirect verifications.
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So we can trust those transactions more then others.
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So now you know what IOTA’s tangle is and how works.
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But how does it stack up against traditional blockchains?
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Well, the tangle solves two big issue’s: scalability and miners.
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Let’s discuss _scalability_.
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As we’ve seen: IOTA’s network becomes faster when more transactions happen.
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This means that IOTA can handle almost an unlimited amount of transactions per second
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while traditional blockchains can only handle a few.
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But there is an other aspect to scalability that most people seem to forget and that is
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storage.
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In a blockchain, you need a full copy of the chain before you can start adding new transactions.
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Right now the Bitcoin blockchain is almost 150GB in size and keeps growing very fast.
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Storing all this data is not something every device can do and will get harder over time.
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IOTA’s Tangle is much more lightweight.
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You don’t need a full copy of the tangle to add transactions.
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You only need a small part of the tangle to create and verify transactions.
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This makes it much more future proof.
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And finally IOTA has _no miners_.
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Usually miners are there to create blocks and validate transactions.
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For this hard work, miners take a fee from each transaction.
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In IOTA, no miners means no fees.
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Sending money around is this completely free!
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So now you know how IOTA’s tangle works, and how it compares to regular blockchain
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technology.
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If you liked this video, please give it a thumbs up and get subscribed to my channel.
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Thank you very much for watching, and I’ll see you in the next video!