Power of UNIX. Simplicity of the Mac.
Mac OS X is both easy to use and incredibly powerful. Everything--from the desktop you see when you start up your Mac to the applications you use every day--is designed with simplicity and elegance in mind. So whether you're browsing the web, checking your email, or video chatting with a friend on another continent, getting things done is at once easy to learn, simple to perform, and fun to do.
Perfect integration of hardware and software.
Since the software on every Mac is created by the same company that makes the Mac itself, you get an integrated system in which everything works together perfectly. The advanced technologies in the operating system take full advantage of the 64-bit, multicore processors and GPUs to deliver the greatest possible performance.
Elegant interface and stunning graphics.
The most striking feature of a Mac is its elegant user interface, made possible by graphics technologies that are built to leverage the advanced graphics processor in your Mac. These technologies provide the power for things like multiway chatting, real-time reflections, and smooth animations.
See also: Mac OS X Snow Leopard, iLife, iWork, Mac Box Set, more responsive, more reliable, photos, movies, and music, iMovie, GarageBand, iWeb, and iDVD