Business TransactionsA business transaction might involve confirming a shipping address, charging the customer and creating an order. If one of these steps fails, all should fail.
File SystemsA file operation such as cut-and-paste whereby the source file isn't deleted unless it is successfully pasted.
HardwareHardware instructions such as test-and-set that involve multiple operations that may be implemented to succeed or fail together.
Long Lived TransactionsTransactions that require business logic to implement atomicity because they take too long to use transaction features of databases such as a two-phase commit. For example, a database update that needs to wait for a batch process to run before it can be finalized.
ProceduresProcedures and policies such as the requirement that passengers and their bags always fly on the same aircraft together.
The guarantee that a series of operations either succeed or fail together.