Summary of Roles
There are several WordPress roles you can give them beginning with the lowest
The Subscriber
Basically all they a can do is edit their site profile
The Contributor
Here they can ‘contribute’ to the site by adding and editing their own WordPress posts, but the finally say on whether they appear is yours.
The Author
This user can do everything a contributor can do, but they are able to publish the post themselves so that it appears on the site.
The Editor
Again, this user has the abilities of the earlier ones, but they can also edit other Author and Contributors posts.
The Administrator
Everything is possible by this type of users, including post and page additions and managagement, site design and menu maintenance.
The Super Admin
As for the Administrator, with the ability to manage WordPress Network features