The basis of blockchains are blocks. These are small units of data containing transactions that account for all transactions in a given period of time. If you transfer some crypto, your transaction will likely be included in the next block. Blocks are mined and added to the chain, creating a blockchain. Each block validates the block before it, thus maintaining a single, permanent or immutable version of the truth. The size of the block determines how much data can be stored on it and the frequency of the blocks or block times determine how many blocks are produced in a given time. The blockchain should contain every single transaction ever made since the beginning of the blockchain.

The little brother of blockchain nodes, light nodes download just enough data to process and verify transactions. Whereas full nodes store a blockchain’s complete history.

NFT domains are minted on the blockchain, such as .ENS or .NFT. They allow the user to set their Web3 username and give them complete ownership of their data. The best use case is that it can be used to replace your ETH public wallet address.

When digital data is stored off a blockchain, for example on a central server, it is considered off-chain. Some NFT projects store the data of their projects this way on decentralised servers like IFPS (Interplanetary File System), but it can incur large long-term costs and be at risk if the server goes down.

An on-chain transaction occurs when the blockchain is modified and verified on the public ledger. On chain data is data that is stored on the blockchain, as opposed to centrally or on IPFS. For example, all @artblocks art is stored as code on-chain.