exotic cars

Lamborghini, Maserati, Bugatti, Ferrari, what do all of these cars have in common? Well besides being really fast, they all are exotic. But here's a question, what makes one car more exotic then the other?  Or how about what makes a car "exotic" in the first place? And why is it people spend so much money on these exotic cars instead of something more meaningful? These are some of the questions that i will be addressing throughout this semester.