PST file is also known as Personal Storage Table file and used to store the e-mail messages, contacts, notes, task and other items of an user. There are many benefits of creating PST file such as:
1) It works as a backup copy for your important data.
2) To keep data as PST file before Outlook/Server get damaged/crashed. You can easily restore it from backup and then use the data in MS Outlook.
3) It can help to avoid data loss situations.
4) You can easily recover your accidentally deleted emails or any other item in MS outlook by restoring it.