Windows 8 is NOT free. Most new computers will come with it pre-installed.
Windows 8 incorporates a new user interface called the "Metro" desktop. Your applications are represent on this interface as individual icons, instead of the familiar taskbar/programs option. The system is designed for touchscreen but works on computers that are not. A load of folks are unhappy with some of the interface changes and Micro$oft is soon to release the 8.1 update to restore some of the older function.
My biggest gripe about Windows 8 is it tends to jump back and forth between the new Metro interface and the traditional desktop. Apps must be written for the Metro environment, otherwise, when you select them the systems throws you back into the older environment. You get used to it - but it can be irritating.
You can click an icon to go to the older desktop and pretty much stay there but, as I mentioned, you'll find an absence of some of the taskbar options you now enjoy. The upcoming update will probably be a nice development.
After all of that ... I've gotten used to Windows 8 and can get around in it just fine. It has its good and bad sides but it performs well. If you will recall, they had some major nightmare releases, i.e. "Windoze ME" and "Vista" that were enough to get people to hang themselves.