Explain ROLLBACK and COMMIT command.The transactions like update, insert or delete can be undone with the help of rollback command. This is helpful when an introduced during your work.
COMMIT can be used to reflect the changes in the database. Until you commit, you can only see how your work affects the tables. Anyone who is accessing the database would be able to see the changes only after you have committed it. This is with the help of CMMIT command