During the registrations process a tradesperson's company might not have a contract setup yet in Eyrus system. For instance; Tom Petty might show up to site but his demolition company "The Concrete Breakers" isn't setup in Eyrus yet. In order to make registrations as seemless as possible you can enter Tom into the system even though he isn't tied to a company yet.
You can think of pending employees as a tradesperson tied to a placeholder company. Once the company and contract for The Concrete Breakers get setup, Tom and anyone else who works for them can now be assigned to company in Eyrus.
To learn how pending tradespeople get assigned see here: How to pending tradeperson get assigned