A Calendly Teams page is a shared scheduling page that allows multiple members in your organization to share their availability and allow others to book meetings with them. It is designed to facilitate team scheduling and collaboration.

Events set up on a team page allow for more control and functionality, including the ability to automate tasks with Workflows. Check out this help center article for more details on getting started: Set up a team page

On the other hand, a Calendly User Group refers to a grouping or categorization of Calendly users based on common characteristics such as their roles, departments, location or any other relevant criteria. User Groups are a feature primarily used for administrative or reporting purposes rather than scheduling. 

You can read about Groups in more detail here: An overview of groups