A Public Microsoft 365 Group or Team SharePoint site data is public and accessible by anyone in the organization.
You will need to make your Microsoft 365 Group or Team private; limit and restrict access to your SharePoint site files and data so only those individuals who need access to it can view your content. If your Microsoft 365 Group or Team handles highly confidential data, you must restrict access to only the individuals that directly need it. Learn more about university data classifications.
If you make your Microsoft 365 Group or Team private, you can still share files with specific users, including users from outside the organization, by using the share options on the SharePoint site or on individual files/folders. You can choose to share files with “view only” or “edit” permissions and set an expiration date or password for the shared link. You can also revoke the shared link at any time if you want to stop sharing the file.
Below are some helpful links about sharing files, folders, and sites in SharePoint: