You know Windows and the Mac desktop? It's basically a free replacement for that.

It does work differently, though it's only different if you're used to Windows or Mac. The desktop looks different for instance, though all it does is start other programs and give you a pretty wallpaper. You'll see different names for programs on top of it, but there are equivalents that are essentially the same; there's often more than one, each do different things better so it's just finding something that works for you. As they're different bits underneath, it means that no Windows viruses or nasties can attack you, too.

There's loads of different ones because all the bits and pieces underneath can be tweaked, just as you can tweak all the programs and stuff on top. Some people have chosen bits to work on servers powering the Internet and huge companies, others have chosen bits just to run their mobile phone. It's a lot more open and customisable. If you don't like one 'flavour' of it, there loads that you can choose, as there's no licensing or anything to restrict you. It's also not under the control of any one company, anyone can join in or just comment on what's happening.

Often problems get shouted over the Internet more so you can find a lot of common fixes. It's always a work in progress and just keeps getting better. There's some that are introduced first to people so attract more support, others are a bit more technical. Again, it's about finding which one works the way you do.