Other forms: blockchains
A blockchain is a shared computer database that's mainly used for keeping records of cryptocurrency transactions. When someone buys or sells Bitcoin, they use a blockchain to safely record the details.
A blockchain works like a shared spreadsheet, with data entered into separate cells or columns. The special thing about blockchain is that once information is put into each block, it can't be changed, making it an extremely secure way to store data. The name blockchain comes from the blocks of data, linked together in chains through cryptography.