Each sim is designed to exactly match the cockpit of a real airliner. In this 747 sim that I flew, you can see the same throttles, control columns and flight information displays that a BA pilot would use to fly paying passengers.
Above our heads was a mass of switches to control the 747's internal systems like hydraulics, electronics and passenger comfort systems. Fortunately, I didn't have to learn each one for my first flight.
You enter the simulators through thin bridges that run to a walkway that runs the length of the room. When a training session starts, the bridge raises like drawbridge so the sim can move in all directions. Here's a sim for an Airbus A380.