Deals lets you gain more insight into your successful sales by learning which deals and memberships your leads are being sold. It lets you go beyond simply counting closes.
Deals can be managed in the settings by account owners and administrators. There you can create new deals, edit existing ones or delete deals you don't want to track anymore.
Once a deal is in the system, when you close a lead you'll be presented with a selection. Simply select the deal being used (or none) and the lead will be closed.
You can run the deals report to understand which deals are performing