Everything in TFS except Active Directory user rights version control are stored in a central SQL Server database. This includes team project settings, file data, changeset details, and so on. Because almost everything is in a central location, it is imperative to make sure you take regular backups of the SQL database(s) and have a disaster recovery plan.
There are three separate windows: the Source Control Explorer, Solution Explorer and Pending Changes windows in Microsoft Visual Studio.
Whenever you work with files under version control and edit, add or delete them, Visual Studio will not immediately commit the changes back to version control. Instead, this is done only when you check the changes in. In the mean time, all your changes are by default stored in a pending changes list, which can be seen through the Pending Changes window.