Followers
The ‘Followers’ feature for Contacts and Opportunities allows multiple users to follow and access the same record. This provides you the ability to add up to 10 users as followers who are able to view and edit the CRM record when the "Only Assigned Data" user permission is turned on
Contact Followers
Followers can be added to contacts on the detailed page of the record.
Opportunity Followers
Add followers to opportunities in the "Opportunity Details" on the Edit/Add opportunity modal