WordPress has certain roles
Super Admin – somebody with access to the site network administration features and all other features. See the Create a Network article.
Administrator – somebody who has access to all the administration features within a single site.
Editor – somebody who can publish and manage posts including the posts of other users.
Author – somebody who can publish and manage their own posts.
Contributor – somebody who can write and manage their own posts but cannot publish them.
Subscriber – somebody who can only manage their profile.
So when you assign a person to editor Role all they can do is publish and manage posts including the posts of other users.
So this is a WordPress function.
See here http://en.support.wordpress.com/user-roles/
This might help tho
http://ww.wp.xz.cn/plugins/user-role-editor/
