Transaction
A record of a cryptocurrency transfer from one address to another. Once confirmed by the network, a transaction becomes part of the blockchain and can no longer be reversed or altered.
See also
Bitcoin
The first and most well-known cryptocurrency, created in 2009 by an anonymous author (or group) under the pseudonym Satoshi Nakamoto. It works without a central bank or intermediaries — every transaction is recorded on a public blockchain.
Blockchain
A distributed database made up of a chain of blocks containing transaction data. Each new block references the previous one, which makes altering past records nearly impossible without the agreement of the entire network.
Hash
A unique, fixed-length string produced from any input data using a mathematical function. The smallest change to the input completely changes the hash, which is why it is used to verify the integrity of blocks and transactions.
Wallet
Software or a device for storing the private keys that give access to cryptocurrency on the blockchain. The coins themselves are not physically "stored" in the wallet — it only holds the keys needed to control them.
Private key
A secret code that proves ownership of cryptocurrency and allows you to sign transactions. Whoever knows the private key has full control over the funds — it should never be shared with anyone.
Public key
A cryptographic key from which a wallet address is derived to receive funds. Unlike a private key, it can be safely shared with others — similar to a bank account number.