Checking out a file with the Microsoft Office Vault Add-in copies the file version in the vault to your local working folder.
Once a file is checked out, it can be edited. Only one member of a team can check out a file at one time. No one else can modify a checked out file until it has been checked back into the vault.
The latest version of the file in the Vault is checked out to you.
If the version you have open is newer than the version in the vault, you are asked if you want to overwrite the currently open version.