The document describes three use cases for LinkedIn: 1) Browsing LinkedIn allows a user to view updates from their connections by scrolling through their home page feed. They can like posts, comment, or view more. 2) Adding Connections enables a user to search for and send connection requests to people or companies. They must wait for acceptance. 3) Applying for Jobs through LinkedIn permits a user to search for companies, view their profiles, and directly apply to open positions listed. They could have their application cancelled or disregarded.