A Session is a single instance of a virtual reality experience that can be shared by multiple users simultaneously. If you can see and hear other people, then they're in the same Session as you.
Try not to confuse a Session with a Location. A Location is the virtual environment that surrounds you, such as a meeting room or garden. A Session takes place in a Location, but each Session uses a separate copy of the chosen Location.
When you're in a Session, you can choose to move everyone in the Session to a new Location. For more information, see Changing Locations.