What is the difference between memory and hard disk space?

By | February 5, 2010

Memory and disk space are perhaps the most widely-confused terms in the computing world. To truly comprehend how your computer works, you must first understand what memory and disk space are.

The hard disk, sometimes called the "hard drive," which is actually the mechanism that holds the hard disk, is a spindle of magnetic discs that can hold several gigabytes of data. Therefore, disk space refers to how much space you have available on your hard disk for storing files. When you save a document or install a new program, it gets stored on your hard disk. The more files you download, install, or save on your hard disk, the more full it becomes.

Memory, on the other hand is not the same as disk space! Memory refers to the random access memory (RAM) inside your computer. These are small chips that hold several memory modules side by side. Your computer uses memory (RAM) to store actively running programs on the computer, including the operating system. For example, the operating system’s interface and other processes get loaded into memory when the computer boots up. When you open a program like Microsoft Word, it gets loaded into the computer’s memory as well. When you quit the program, the memory space is freed up for other programs.

RAM can be accessed several hundred times faster than a hard drive, which is why active programs must be loaded into the RAM from the hard drive. Because most data on the hard disk does not need to get loaded into the system memory at one time, computers typically have much more hard disk space than memory. For example, a computer may come with a 200 GB hard drive, and only 1 GB of RAM.

So if your computer tells you that you don’t have enough space to install a program, you will need delete files from your hard disk that you don’t need or buy an additional hard drive. If your computer says there is not enough memory to run a certain program, you will need to upgrade your memory by buying more RAM. Knowing the difference between these two types of hardware can save you precious time and money.