Explanation for deciding user rolls
Administrator – add, edit and delete all posts. Install, edit and delete plugins and themes. Create, edit, change user information, including changing passwords and delete user accounts.
Editor – full control of content sections, can add, edit, publish any posts, moderate, edit and delete comments.
Author – write, edit, delete their own posts.
Contributor – create, and edit their own posts, but not publish.
Subscriber – can log on to WordPress site, update profile and change password. Can not write posts, view comments or anything else in WordPress admin.
Super Admin – has Administrator-level access to all sites in your network. This user also has the ability to add new sites, manage users, and manage network-level settings. Since this user has access to all settings network-wide, you should be very careful when considering who has Super Admin privileges.