Imagine a giant shared spreadsheet that everyone can see and contribute to. That's kind of what a blockchain is. It's a special type of database where information is stored in blocks that are chained together. Each block contains information about transactions, and once a block is added to the chain, it's very difficult to change it. This makes blockchains very secure and trustworthy. Blockchains are most famous for being the technology behind cryptocurrencies like Bitcoin.
