As the speed and storage capacity of home computers continue to grow, consumers have been confronted with an escalating series of terms to describe quantities of data: "megabyte," "gigabyte" and even "terabyte." Most people know a gigabyte is bigger than a megabyte, but without a good idea of what these terms mean it's hard to appreciate how much more storage a gigabyte represents.
Breaking it Down: What's a Byte?
In computer parlance, a "bit" is the smallest piece of digital information -- basically, off or on, usually represented as zero and one. A "byte" is eight bits. Since each bit in the byte can be in one of two states, zero or one, the total information storage of a byte is two to the 8th power, or 256 bits. A kilobyte (often known simply as "K") is often referred to a 1,000 bytes, but more accurately it is two to the 10th power, or 1,024 bytes.
As we move up the scale of data storage, increase by orders of magnitude. Just as a kilobyte is 1024 bytes, a megabyte is 1024 kilobytes, or 1,048,576 bytes. Since a page of ASCII text is about 5 kilobytes, a megabyte would store about 200 pages of text. A megabyte is also enough to store about one minute of CD-quality audio in MP3.
A gigabyte is 1024 megabytes, or more than one billion bytes. This is equivalent of more than 200,000 pages of text storage, or enough to store more than 350 standard-length MP3 files. A gigabyte will store about one and a half minutes of High Definition video.
The next step up is the terabyte, or 1024 gigabytes. Once the province of supercomputers, one terabyte storage drives are now showing up on the home market. A terabyte is more than one trillion bytes of information, or more than 200 million pages of text. A terabyte drive is large enough to store about 24 hours of high-definition video.