If you are unsure of how a feature works, one of the best ways to understand how it functions is to use the VolunteerKinetic demo site. This is a full system identical to your own but it contains dummy data.
You can access the DEMO SYSTEM by going to: demo.volunteerkinetic.com
The three buttons on the homepage of the demo site allow you to login as either a Volunteer, Provider or Administrator. The data is refreshed every night so you can test the various functions without the worry of effecting your data.