What is Blockchain?
A blockchain is a public ledger (or file) of transactional data, distributed across multiple computers (“nodes”) in a network. All of these nodes work together, using the same set of software and rules, to verify transactions to add to the finalised ledger.
The “block” part of “blockchain” refers to a set of transactions that are proposed and verified by the other nodes and eventually added to the ledger. The “chain” part, refers to the fact that each block of transactions also contains proof (a cryptographic hash) of what was in the previous block. This pattern of capturing the previous block’s data in the current block continues all the way back to the start of the network (the genesis block) creating a publicly verifiable and tamperproof record of all transactions, ever.
Practically, this means that if you try to change even a single record, anywhere in the history of a blockchain, it will be evident and rejected by the network nodes.
But how do blocks get added to the chain in the first place? Each node runs software that instructs them how to verify transactions and add new blocks to the chain. These instructions are collectively referred to as the “consensus protocol”. The nature of these instructions are one of the main distinguishing factors of different blockchains
What is a smart contract?
Smart contracts are on-chain logic programs that can implement highly customised transfer conditions. They can be composed with all other layer-1 features, (including Algos, NFTs, fungible tokens) to produce powerful and sophisticated decentralised applications.
More information can be found here
What language can I use to write smart contracts?
what is a dApp?
Decentralized Applications, or dApps, are applications that are run in a decentralized computing system, like a blockchain. You can find out more about dApps here: