A series of games from Sony's Polyphony Digital studio, created by obsessive car enthusiast Kazunori Yamauchi.
That aim of the series is to simulate 'The Thrill Of Driving' for its users.
The physics of the game were a revolution at the time of the first release, being based around a model for the contact of the tyres on a road surface, which was then influenced by physics modelling for the weight, and particularly weight distribution over those tyres dependent on the model of car the user was driving.
The series has been hugely successful amongst established gamers, but also managed to create an appeal that bridged the gap to car enthusiasts. This lead to articles/reviews appearing in established car magazines, as well as being prominently featured in Motoring shows such as the BBC's Top Gear. As such this has made the series a key player in tapping into a wider customer base for sales of playstation hardware.
Kazunori made it clear early on in the development of the series that he was attempting to make a racing simulator in a more accessible, realistic way. The logic he applied in this was that any basically proficient driver would have the skill to take a reasonably powerful car out on a race track and drive it successfully at lower speeds without spinning off the track. Driving that same car around the same track at great speed however would take skill and control.
Gran Turismo has been a flagship franchise for Sony, and has only appearead on PlayStation hardware. With over 60 million copies sold worldwide, it's the highest-selling of any PlayStation exclusive series.