# Overview of Transactions

Let us go through the details related to Transactions.

• We typically perform operations such as COMMIT and ROLLBACK via the applications.

• COMMIT will persist the changes in the database.

• ROLLBACK will revert the uncommitted changes in the database.

• We typically rollback the uncommitted changes in a transaction if there is any exception as part of the application logic flow.

• For example, once the order is placed all the items that are added to shopping cart will be rolled back if the payment using credit card fails.

• By default every operation is typically committed in Postgres. We will get into the details related to transaction as part of application development later.

• Commands such as COMMITROLLBACK typically comes under TCL (Transaction Control Language)