There are a number of roles in WordPress, all flexible calibers so you can give your friend full access and keep strangers away from your source code. Let’s take a look at the tiers, huh?
Admin
Admins are typically the site creator and co., and have all permissions with the site. It is UNINTELLIGENT to allow anyone you don’t know to have the abilities this role brings, so BE SMART! There’s a subset of this called the Super Administrator, who has full control over the entire site network. A very powerful person.
Editor
Editors are, at core, debuffed admins. There’s loads they can do, and loads they can’t do. Still, they can do plenty in the settings, unlike any weaker tiers.
Author
Authors can write and post content on a site freely, but can’t touch anyone else’s stuff. Some sites have dozens of them.
Contributor
Contributers can change and add to specific projects and pages, but need editors or admins to review and post their content.
Subscriber
The only capability of a subscriber is access to read anything they want on a site. Only, they can’t change anything. Subscribers don’t tend to get given a big workload, at least.