One question I am often asked is, "what is the difference between hard drive and memory?" A hard drive is a magnetic disk that stores information for the long-term. In Windows, you can view the contents of your hard drive by double-clicking on My Computer and then double-clicking on the C: drive. The hard drive stores all of your files and programs and provides the starting point for starting up Windows when you turn on your computer.

If the hard drive does all of this, you might be asking why you still need memory? The answer is that the hard drive is extremely slow by itself. If you were comfortable waiting a full day to turn your computer on, the hard drive might suffice by itself.

Memory also known as RAM (Random Access Memory) stores information from the hard drive temporarily in order to give you the fastest possible access. Memory cannot store files when the computer is turned off. In technical terms, memory can access information in nanoseconds while the hard drive accesses information in milliseconds. A millisecond is a thousandth of a second, while a nanosecond is a billionth of a second. If your computer is ever running slowly, a quick and inexpensive fix is usually to add more memory because your system will be able to run more information from memory and less from the hard drive. Both memory and hard drives are measured in MB (Megabytes) and GB (Gigabytes).