Atomicity is a property of database transactions that ensures they are completed fully or not at all. This means that if a transaction involves multiple operations, either all of them succeed, or none do. This all-or-nothing approach helps maintain data integrity, preventing partial updates that could lead to inconsistencies. In the context of computer science, atomicity is crucial for systems that require reliable data processing. For example, in a banking application, transferring money from one account to another must either deduct the amount from the first account and add it to the second, or revert both actions if any part fails. This guarantees that the state of the database remains consistent.