Blockchains aim to keep a safe and unchangeable record across many computers. This network is called nodes. They protect data using special codes. When a transaction is made, miners work to check it and add it to a block. They solve math puzzles to do this. Once they succeed, the block joins the chain. Miners get rewarded with digital currency for their work. Every block is stamped with the time and linked with others securely, making a strong chain.