During qualifying, cars obviously need to come in and out of the pit lane... a lap immediately after exiting the pits is called an 'out lap' and a lap that ends with a car coming into the pits is an 'in lap'. Any other laps are 'full laps' where the car starts and ends the lap by crossing the start/finish line. A 'hot lap' is any full lap attempted at full pace. Optimal qualifying conditions are fresh tyres and only as much fuel as is needed to complete one three-lap set of 'out lap', 'hot lap' and 'in lap', but sometimes drivers will stay out for longer, so long as they have enough fuel to do so.