Something that lets the government stalk u when you've been a bad person. of something that lets creepers find u when u post too many pictures of yourself on the internet and give out too much personal information to people u don't know.
An IP is really an internet address. Like your home pagina address, but on the computer. u don't need to know it really, but I do suggest u write it down on a piece of paper somewhere because some sites use it as protection after u get hacked and such. But yeah, it's basically a code that people use to track you, too.