You might be wondering: “what’s the difference between managing my Page and my Ads?
Some users may not require an explicit page role but only an ad one for their job requirement and responsibilities. As with the Page Roles, the Ad Account roles can be added easily, this time using the Ad Account Settings in the Ad Manager of your page. This can be done by either searching for the name of the person if you have them as a friend on Facebook or through their email account. As with Facebook Page roles, each role has specific permissions as shown below, these can also be found at the following link
The roles that can be assigned for the Ad account are Ad Account Admin, Ad Account Advertiser and Ad Account Analyst, each with similar permissions as those same titles in the page roles.