Blockchain technology is the backbone of most cryptocurrencies. A blockchain is essentially a digital ledger that records all transactions made with a particular cryptocurrency. It is maintained by a network of computers (often called nodes), each having a copy of the ledger. Whenever a new transaction occurs, it is added to a block, which is then linked to the previous block, forming a chain. This process ensures the security and integrity of the network, making it extremely difficult to alter past transactions without the consensus of the majority of the network.