Linux is a free *nix like operating system. To be accurate, "linux" is only the kernel, the "heart" of the operating system, developped by Linus Torvalds.

To use Linux, one needs to add a lot of other programs that together lets you use the operating system. These programs must be compiled against compatible libraries, and it helps (a lot!) to have some installation program that lets you configure and install your system.

All these things together make a distribution. there are many ways to achieve this, and many more choices to be made, that's why there are so many distributions around. From the "easy to install for beginners" to the "Compile and tweak everything to your taste", there are distributions for every taste.

If you understand how to use a computer, Linux is NOT difficult to learn to use - this is an old tale from the first years, when there was as good as no installer. But you must learn how *nix works to use it.
If you're not willing, no problem: stick to what you're using. But if your are willing, Go to the next pane to get more information about the distributions I like - there is always a distribution for you...