The staffer workflow is the set of states the staffer may traverse as they register at Watu, get approved, suspended, etc.
When someone starts the registration process, they are put in state "registering". You can completely ignore them. Quite likely you'll have a lot of garbage in there. That's all right.
Imported is similar to registering. People that are imported, like those registering, cannot do anything at Watu except fill up their profile. Imported is used when you upgrade from an older system to Watu.
One registering or imported staffers finishes entering all their data and pictures, those staffers are automatically put into pending mode. That's when you, as a manager, come in. You'll have to decide what to do with these applications. You might want to run some google searches, do interviews, etc. That's up to you as an agency, but essentially you have to options: accept them or decline them.
Staffers while in pending can do more things in Watu, but not a lot. You can invite them or book them into jobs, but they cannot see the list of jobs.
Once you accept them, they are active members and they'll have access to everything they can do, including applying to jobs.
If you decline them, they won't be able to log in into Watu. That's how you get rid of applications you don't want, whether it's just garbage, spam or just someone that's not a good fit for your agency.
The last piece of the puzzle is suspending. If you have an active staffer with whom you don't want to work anymore, you suspend them. A suspension can be permanent or temporary. It might be because the staffer took a sabbatical and went to Antarctica or because they didn't perform well. In the latter case, you can specify what's going on with a warning note. Suspended staffers can be re-activated.