Skateboarding is riding and performing tricks with a skateboard. Some one who skateboards is called a "skater".Skateboarding can be seen as an artform, a job, or a way of getting around mostly the boards used for transportation are longboards. In 2002 it is reported that there were 18.5 million skateboarders in the world. 85 percent of skaters who were counted last year were under 18, and 74 percent were male. A key trick, the ollie, was invented in the 70s by Alan "Ollie" Gelfand. Skateboarder Rodney Mullen was the first person who invented the kickflip and its variations like the 360 flip or better known as the"tre flip"