Commit is the transactional command used to save changes invoked by a transaction to the database it saves all transactions to the database since the last Commit or RollBack Command.

commit finds all breakpoint which marked for either delete or update operation , than it will complete updation on defined breakpont

Commit permanently save the transaction after commit we can rollback transaction.......

Use the COMMIT statement to end your current transaction and make permanent all changes performed in the transaction. A transaction is a sequence of SQL statements that Oracle Database treats as a single unit. This statement also erases all savepoints in the transaction and releases transaction locks.

hi how are u all of u...?

Marks the end of a successful implicit or explicit transaction.

after changes are made and user commits it,it cant be undone or in SQL rollbacked.

Commit is a TCL  command which is  used to make  database 
transaction permanent.
once the data is commited it can't be rollbacked.

COMMIT makes permanent the changes resulting from all SQL statements in the transaction. The changes made by the SQL statements of a transaction become visible to other user sessions transactions that start only after transaction is committed.