Hi Ventas64530!

Here’s an overview of “paid seats” and “users” within Calendly: 

Purchasing Calendly subscriptions for your organization is like purchasing desk chairs. Once someone joins your organization, you purchase a desk chair for them. When that person leaves, you have an extra desk chair to use or to get rid of. At Calendly, we refer to these desk chairs as paid seats. 
 
When you add a new user to your organization's Calendly account, you automatically purchase a paid seat on the account. The new user will receive an email invitation to join your account, and they'll get their own account and Calendly page, along with whichever event types you assign to their account. You'll also be able to include them in team scheduling.
 
If you remove a user, their paid seat remains. That way, you can invite a new user to your organization without needing to purchase an additional seat. If you do not plan on inviting another user, you will want to remove the remaining paid seat from your Billing page.

I hope this helps!