Apple Computers — more commonly referred to as "Macs" (short for Macintosh) — are the family of personal laptop and desktop computers designed by Apple and marketed under names like the iMac and the MacBook.
The machines all use some form of Apple's OS operating system (usually OS X), and run on protocols uniquely different from PC machines, which most often use Microsoft's Windows operating system. Now, you know what all those TV commercials with Mac guy and PC guy are all about.
Mac users tend to be very passionate about their computer of choice. Most will tell you the Mac experience is a more intuitive one, as opposed to PC users, many of whom like their computing to be more analytical. Many Mac users are also quite vocal about the fact that Apple machines are less prone to viruses and malware than their more widely used Windows based PC counterparts, although there are also those who will dispute this.