People can be marked as inactive in VSys, meaning that they are not currently participating but may do so again in the future. Use an inactive status when someone is temporarily not volunteering. This allows you to track and report on why your volunteers might be taking a break from volunteering. The "inactive" status is designed for volunteers you expect to return. If you expect they are leaving permanently you would probably want to archive them as well.
Define inactive reasons from the Setup panel under by clicking on Inactive reasons. Add the reasons you want to track.
Deleting an inactive reason removes that reason from all people who currently have it, but does not make those people active.