Manage Access to Team Files
From Help Wiki
- Default access to files/folders gives access to all Team Members (no extra steps required).
- Private channels limit file access to those Team members who are also defined as being a member of the private channel.
- You can "Manage Access" to files and folders via the SharePoint link. Here you can limit the ability for Team members to edit a folder/file or you can even stop sharing altogether.
- You can also assign Direct Access to specific people (even people who are not members of the Team).
Resources: Overview of Sharing Files in Teams https://docs.microsoft.com/en-us/microsoftteams/sharing-files-in-teams