A shared ledger
A blockchain is a distributed record whose participants validate and append data according to network rules.
Blocks and hashes
Transactions are grouped into blocks. Cryptographic hashes link records and make unauthorized historical changes easier to detect.
Consensus
Consensus mechanisms define how a network agrees on valid state. Different networks make different tradeoffs in speed, decentralization, cost and security.
Tokens and networks
A coin may be native to one network while a token can exist through a smart contract. Network selection matters when depositing or withdrawing assets.
Practical risk
Blockchain settlement can be irreversible. Always verify the asset, address, network and memo requirements before sending funds.