While Microsoft Windows does not really need an introduction, it is probably worth giving a brief introduction to Ubuntu. In short, Ubuntu (pronounced oo-boon-too) is a very popular open source operating system based on the Linux kernel. It has enjoyed increasing popularity because it is easy to install and very stable. Ubuntu can be installed either as a server operating system without a graphical interface, or as a desktop operating system with a graphical interface that closely resembles Windows.
You can learn more about the Ubuntu operating system, and why it is so popular, at http://www.ubuntu.com/.
