# A Big Byte

Bits and bytes are terms that are used constantly when talking about computers. And there’s good reason, because the words describe data and disc space, or disc storage space, as well as the memory in a computer system. But just what do they describe? Here’s a quick lesson, but hold on — your brain might explode.

• Bit: A bit is the smallest unit of data that a computer can use. Think of very basic computer language: 1 and 2 or Yes and No.

• Byte: A byte equals eight bits. You can figure about one byte of data equals one character. Ten bytes could equal a word. About 100 bytes would equal an average sentence.

• Kilobyte: A kilobyte is approximately 1000 bytes. That would be enough data to equal the length of this paragraph you are reading. 100 kilobytes would equal an entire page of text.

• Megabyte: A megabyte is 1000 kilobytes. It wasn’t all that long ago that a megabyte was considered a lot of data. It still is, but technology has advanced to the point that computers and hard drives can hold a lot more. About 1.5 megabytes would equal a small book while 100 megabytes could equal a couple volumes of encyclopedias. Thirty seconds of video in high definition would equal roughly 200-250 megabytes of data. The higher resolution the camera, of course, the more data is required to record the photo or video. Most CD-ROM discs hold 600-700 megabytes of data.

• Gigabyte: A gigabyte is approximately 1000 megabytes. More and more disc drives are able to hold this amount of data. One gigabyte is roughly the amount of information contained in 10 years of books on a shelf.  A six-minute video in high definition will take about one and a half gigabytes of data. One hundred gigabytes is about the amount of information on an entire library floor.

• Terabyte: A terabyte is 1000 gigabytes. One terabyte would contain 1000 encyclopedias while 10 terabytes would contain all of the information in the Library of Congress. Hard drives that will hold a terabyte of data are becoming more common.

And if your brain isn’t hurting yet, the next unit of data measurement is the… Petabyte. Yep, that’s 1000 terabytes. If you can imagine 500 billion pages of books, you’ve got an idea of how much data is contained in a petabyte. Start reading!!!

And if you’re a really fast reader, there’s the… Exabyte. You guessed it. That’s about 1000 petabytes. I’m not even going to go there.

— Frank Graff

Frank Graff is a producer/reporter with UNC-TV, focusing on North Carolina Science Now, a weekly science series that airs Wednesdays, beginning in August 2013, as part of North Carolina Now on UNC-TV. In addition to producing these special segments, Frank will provide additional information related to his stories through this North Carolina Science Now Reporter's Blog!

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