Personal Storage Table
The personal storage table file is better known as the PST file and displayed as .pst. This is a Microsoft Outlook Data file storing the data for an Outlook user for IMAP, POP3 as well as other web email accounts. It includes all email folders and the content of all these folders like the emails and attachments, contacts and appointments etc. Personal storage table file is used by every version of the Microsoft Outlook, whether it is Outlook 2000 or Outlook 2010. In the earlier Outlook versions, these files had been stored in ANSI formats while the later versions store the PST files in a Unicode format.
The PST files may be compacted through the “Compact Now” button on the Outlook’s file management section. The corrupted PST files may be repaired through either ScanPST application under Microsoft or by a third party application. The OST file is an offline storage table which works like a cache for the Outlook; this stored the archived versions of the user’s Outlook data on local computers instead of on mail servers. This allows users to access the items even when the server is not available. The OST files are bound by the email configurations and cannot be opened and backed up separately. So, OST files may be in the same format as PST files except that they are used for offline storage of emails. PST files have been designed for email archival.