Sessions are the ultimate container that will help you plan game time with your players. You will fill a Session with all of the Game Objects, Locations, Events that you feel could happen during the game and add them to the Session. Use it as a quick table of contents for what you expect your players to accomplish during a session. If they don't accomplish everything? You can, from that very session, create a new session with those pieces of Lore they didn't yet experience!