Blockchain in terms of bitcoin Bitcoin aims to decentralize currency and replace traditional currency; Ethereum aims to decentralize the app world Ether is the currency that runs on Ethereum – you need to spend ether to execute smart contracts, which is what gives ether its value
To fully understand immutability, we must understand how blockchain works
Decentralization means that no one node controls what happens in the network. Decisions are made by achieving consensus among the nodes, and all nodes around the world maintain the same ledger and update whenever there is a change.
So let’s say I in Toronto
Want to sell my house to you, in Vancouver
We must first propose this transaction and perform the necessary proof of work to have this transaction approved, and then when we reach consensus,
That transaction gets added as a new block in the chain, and every other node in the network updates their chain to include it.
Now keep in mind that this is all happening very quickly – in fact most blockchains average 3-7 transactions per second.
This mathematical linking is what makes a blockchain immutable – each block is, in part, composed of the block that came before it. It is therefore impossible to change one block in the chain without breaking the whole thing.
NOTE for PDF viewers: this slide builds
Ethereum is both a blockchain network and a technology. The Ethereum networks employees the technology, but one does not have to subscribe to the Ethereum network in order to use the Ethereum technology. It allows users to create their own blockchains for whatever reason he or she sees fit, and that blockchain can be publicly shared or privately shared depending on how it is applied.
Ethereum is a general purpose blockchain that still has all the concepts of those designed for cryptocurrencies. Ethereum nodes mine “Ether” as the currency that is exchanged in Ethereum networks.