You may create as many AutoNumbers schemes as you want for each type of records (contact, company, groups and opportunities).
Some of your AutoNumbers might run automatically when creating a record but some you might want to run manually as needed. It might be to periodically generate a unique quote
or way bill number.
For these AutoNumbers that you run manually, you might want to add a button to your layout so that you don't have to open the AutoNumbers add-on interface every time.
Here is a video showing you how to add a button to a layout and assign it an AutoNumber scheme.