11.2.4. About Transaction Participants
A transaction participant is any process within a transaction, which has the ability to commit or roll back state. This may be a database or other application. Each participant of a transaction independently decides whether it is able to commit or roll back its state, and only if all participants can commit, does the transaction as a whole succeed. Otherwise, each participant rolls back its state, and the transaction as a whole fails. The Transaction Manager coordinates the commit or rollback operations and determines the outcome of the transaction.