A speedrun is a video of a player beating a video game as fast as he possibly can. He can choose to run through the entire game in a single sitting (this is called a single segment speedrun), or he can split his run into several parts (a segmented run).

While the main purpose of speedruns is to provide entertainment to watchers by showing off high level gameplay, there is always competition between runners, and only one will get the fastest time. : )

For more information about speedruns, visit the Speed Demos Archive (SDA):

http://speeddemosarchive.com

There you can also download and watch hundreds of speedruns, free of charge, aswell as be a part of the largest speedrunning community on the internet.

I'm really 18.