Have you heard the one that says that Mac OS X is resistant to viruses? The claim sounds like slick marketing or maybe an urban legend. The truth of the matter, however, is that Mac computers are actually very unlikely to have problems with viruses—not necessarily because of superior design, but because of a few simple facts about how computers and viruses work.
When people talk about Mac computers, they can be referring to two separate features—hardware and operating system. Hardware includes the physical parts of a computer. The Mac OS X actually uses hardware very similar to Windows computers.
When people talk about the Mac OS X being resistant to viruses, they are not talking about hardware, but about the operating system. An operating system is a set of software stored on a computer. This software allows you to communicate with the computer. Operating systems translate information from hardware into information that is usable both to software applications and to you.
So why is the Mac OS X operating system vulnerable to fewer viruses than Windows? To understand this, you must understand a little bit about how computer viruses come into existence.
Viruses do not spontaneously pop into existence. They must be specifically programmed to work, by real people who strategize about how to make their viruses most effective at infecting computers and spreading themselves around.
Viruses target software. They corrupt files, hide in seemingly harmless places, and use the existing communication systems of computers to copy and spread themselves. In effect, a virus is a kind of computer program—admittedly one that no one would ever want or install intentionally.
So why is this important? Well, the people who design viruses, for whatever reason, want them to spread efficiently. But a virus cannot be compatible with both the Mac OS X operating system and Windows at the same time. Because fewer people use Mac OS X than Windows-based computer, designing a virus for Mac computers is a great way to ensure that most people will never even see the virus.
If a virus which runs on the Mac OS X operating system manages to copy itself onto a machine running a Windows operating system, the virus will simply not work. The reverse is also true; a virus designed for Windows machines will not run if copied to a computer running Mac OS X.
Mac computers rarely experience viruses, but as you can see, this is mainly because a virus designed for Mac OS X has minimal chances of spreading.