Each of the 6 Facebook Page Roles allow you to edit or view different things on a Facebook Page. Admin, Editor, Moderator, Advertiser, Analyst or Community Manager.
Admin, allows access with full control of all tasks, Page Roles and Page Settings.
Editor, allows all tasks except the ability to manage Page roles and settings.
Moderator, allows task access for message replies, community activity, ads & insights.
Advertiser, allows task access for ads, insights.
Analyst, allows task access for insights.
Community manager, allows access to moderate live chats.
For a detailed breakdown of the permissions allowed in each Page Role, check out the latest official Facebook guide here: https://www.facebook.com/help/289207354498410