The new Sales Team Member app is designed for the lightweight sales scenarios where users don’t need the full capabilities of an enterprise application. This app is included with the Team Member license.
At a high level, users with the Team Member license can perform the following tasks in the Sales Team Member app:
1) Customer management: work with contacts or see accounts.
2) Lead and opportunity management: see leads or opportunities linked with accounts or contacts, or see other sales-related data.
3) Add notes and activities, such as tasks.
These restrictions were not really enforced as of now and users that has been assigned a Team Member license would not be restricted from accessing Quote or Invoice records in the system.
Microsoft has announced that they would start enforcing the restrictions and to aid customers with compliance, it is now shipping an APP that is designed for Team Member license users.
The Sales Team Member APP is now available in organizations that has Sales Hub app already installed. Along with the APP, it also ships this security role named as Sales Team Member.
Hope this helps.