Administrator
An administrator has full and complete ownership of a blog, and can do absolutely everything. Complete power over posts/pages, comments, settings, theme choice, import, users – the whole shebang. Nothing is off-limits, including deleting the entire blog. Can edit and view private pages.
Editor
An editor can publish, edit, and delete any posts/pages, moderate comments, manage categories, manage tags, manage links and upload files/images. Can edit and view private pages
Author
An author can edit, publish and delete their posts, as well as upload files/images
Contributor
A contributor can edit their posts but cannot publish them. When a contributor creates a post, it will need to be submitted to an administrator for review. Once a contributor’s post is approved by an administrator and published, however, it may no longer be edited by the contributor. A contributor does not have the ability to upload files/images.