Every Macintosh uses the Mac OS X operating system. However, dozens of different versions of the Mac OS X system have been released to date, such as version 10.4.11, 10.5.7, and 10.6. Many programs won't work if your computer uses a version of the Mac OS X program that doesn't meet the software publisher's requirements, so you need to know which version your computer is running before you buy.
In addition, many programs won't run unless your Macintosh has a minimum amount of available memory. For example, if your program needs 2GB (gigabytes) of RAM but your Macintosh has only 1GB of RAM, you can't run that program, even if your computer uses the correct version of the operating system. (If all this talk about RAM and gigabytes confuses you, relax. You simply need to know how much memory your computer has and don't need to get bogged down in the technical details.)
Note
The amount of memory (RAM, which stands for Random Access Memory) that is considered the bare minimum is 1GB, which is perfectly fine for word processing, using email, or browsing the Internet. If you plan to do more heavy-duty computing, such as spreadsheet number crunching, computer-aided design, or desktop publishing, you could get by with 1GB, but most high-end programs need at least 2GB. Of course, the more memory you add, the faster your Macintosh will run, since it can automatically detect and use all the memory available.
Some programs are also picky about the speed of the processor used in your computer. Since the processor acts like the brain of the computer, some programs won't run unless your computer has a certain type of processor that operates at a specific minimum speed (typically measured in gigahertz, or GHz). If your computer processor speed is too slow, it may not be capable of running certain programs.
Note
The two types of processors used in the Macintosh are PowerPC and Intel processors. PowerPC processors were used in older Macintosh models, while Intel processors are used in all newer Macintosh models. Mac OS X 10.6 Snow Leopard can only run on Macintosh computers that use Intel processors.
Fortunately, the Macintosh makes it easy to determine which version of the Mac OS X operating system is running on your computer, the total amount of RAM available, the processor type, and processor speed. Simply do the following:
Click the Apple menu and choose About This Mac. An About This Mac window appears, as shown in Figure 49-1.
Click the close button of the About This Mac window.
