Why is parkour and freerunning popular among teenagers?

Around the world among not only teenagers but also adult people, parkour and free running  are done and are considered to be a really cool things to do. First of all, what are parkour and free running like? “Parkour is a form of movement that stresses efficiency and speed, requiring you to get from point A to point B as quickly as possible while putting jumps, tricks and flips into your route. Free running is similar, but it also involves movements such as flips, spins and many other forms of flair”. If you’ve seen people doing crazy jumps over railings and through cities, they are probably practicing parkour or free running.