OST and PST files are very important for the proper functioning of Outlook, however there are marked differences between both these files and the way they function, this is why it’s important to explore the OST vs PST topic further.
Personal Storage Table or .PST file
The .PST file is generally created for POP accounts setup on your Outlook. It serves as a database which stores all your contacts, emails, calendar entries etc. PST files can be imported into Outlook easily and used independent of the system or Outlook profile that created them. It is for this reason that they are extensively used for archiving mailboxes from the Exchange to free up resources.
Offline Storage Table or .OST file
The .OST file, simply put, is a local copy of your exchange mailbox. This serves the purpose of allowing you to work on your mailbox and other items even when not connected to the Exchange Server. The changes you make are synced with the exchange server whenever the connection is back live.
OST vs PST
When we talk of OST vs PST, the main difference between these two types of Outlook data files from a usability standpoint is that OST files cannot be accessed independent of the Outlook profile that created them which limits their transferability, whereas PST files can be transferred between computers and be accessed independent of the Outlook account that created them. There no way to view OST contents directly whereas you can use import PST into Outlook and access the data within easily. Also, to be noted is that OST files sync automatically with the Exchange Server whereas PST files don’t.
In case you have an orphaned OST file and need to view its contents, you can use the EdbMails OST viewer tool to do so. EdbMails also supports conversion of OST to PST and direct migration of OST to Office 365 and Live Exchange Server making it a perfect solution for all your OST Recovery needs.