To view address books other than the default, in Mail, on the Home tab, in the Find group, click Address Book. Then in the Address Book box, click the address list that you want to view.
The Outlook Address Book is a collection of address books or address lists, created from your Outlook contact folders. If you use Outlook with a Microsoft Exchange Server account, your Address Book list will include the Global Address List (GAL). The GAL contains the names and e-mail addresses of everyone that has an account with that Exchange Server and is configured automatically by Exchange.
You can add and modify records in your personal address books. However, only the system administrator can add and modify records in the system address book.