Atomicity

Modern database systems are governed by the ACID principle.[1] In that context, several operations can be grouped into what is called a transaction. From the outside, there are two points in time: before the transaction, and after the transaction. If one operation of this transaction fails, the whole transaction will. In other words: Either all the operations are done, or none is. An example of an atomic transaction is a monetary transfer from bank account A to account B.