A blockchain is a digital database in which transactions are stored permanently. It is not kept on a central server but as an identical copy on thousands of computers worldwide, the so-called nodes.
Transactions are collected in blocks. Each new block contains a digital fingerprint (hash) of the previous block. This links all blocks together. Anyone wanting to change an old entry afterwards would have to recreate that block and all following ones, at the same time on the majority of all nodes in the network. That is practically impossible.
What this means for you
- Transparent: Every transaction is publicly visible, for example via BscScan or Etherscan.
- Immutable: Once something is confirmed, nobody can undo it. Not even a transfer to the wrong address.
- No middleman: There is no central authority that approves or blocks transactions.
Well-known blockchains are Bitcoin, Ethereum and the BNB Smart Chain.