Database
In most databases, data can change. This also means, that in many cases, changing the data needs to be done in several steps. This is because the data is often stored in more than one tables or files that need to work together to make sense. In many cases all the steps that are needed for a given change are grouped in what is called a transaction. If something goes wrong, all the steps are undone. Being undone is another way of saying the transaction was rolled back. If all the steps are successful, they can be made a permanent part of the database. People talk about a transaction being committed. Both rollback and commit affect all the steps in a transaction.