What are the Difference between PST and OST Files?

MS Outlook is a popular email client application developed by Microsoft Corporation. It is a part of Microsoft Office suite, and it comes as a separate application as well. It is a personal information manager that is mainly used for emails. Additionally, it includes some useful features and functions, such as: calendars, contact management, task management, note taking, journal and web browser. MS Outlook can be used as a stand-alone application for individual purpose, and can be used with Microsoft Exchange Server and SharePoint Server for business or organizational purpose. You can configure or add single as well as multiple email accounts in Outlook.

Difference Between PST and OST

MS Outlook creates an Outlook data file to store all the email messages and other mailbox data, such as: contacts, calendars, tasks, notes, appointments as well as attachments. Each configured email account has its own PST file. If you are using Outlook as a stand-alone application, then it creates Outlook data file in PST aka Personal Storage Table format. But if you are connected with Microsoft Exchange Server and the “Use Offline Folders” option is selected in Outlook, then OST file is created to store your mailbox data in an offline folder on a local computer. You can use or access OST file with ease if you are offline or not even connected with the Exchange Server.

The major difference between PST and OST files is that an OST file can be accessed offline, while a PST cannot. OST files are quite similar to PST files, but they support larger file sizes.

Also read: Popular Email Client Applications