Most computers come with just one operating system, which is usually all you need. However, if you feel like trying out a different one later, you don't need to get a whole new computer. Dual-booting ...
I used to be a Linux distro hopper. I'd bounce around from one operating system (OS) to another. I'd move from Red Hat to Mandrake, to SUSE and then Ubuntu, and from Bohdi onto Elementary OS, and on ...