Glossary

A zettabyte is 2 to the 70th power, or 1,180,591,620,717,411,303,424 bytes.

It can be estimated as 10 to the 21st power, or 1,000,000,000,000,000,000,000 bytes. A zettabyte is 1,024 exabytes and precedes the yottabyte unit of measurement. Because of the enormous size of a zettabyte, this unit is almost never used. The prefix zetta comes from "Zeta," which is the sixth letter of the Greek alphabet.

For a list of all the different units of measurements, view this Help Center article.

Abbreviation: ZB

Windows users will see this term a lot when looking for files on the Internet. A zip file (.zip) is a "zipped" or compressed file. For example, when you download a file, if the filename looks like this: "filename.zip," you are downloading a zipped file. "Zipping" a file involves compressing one or more items into a smaller archive. A zipped file takes up less hard drive space and takes less time to transfer to another computer. This is why most Windows files that you find on the Internet are compressed.

To use a zipped file, you'll need to unzip it first. PKZIP for DOS, or WinZip for Windows, are some popular programs that can unzip files for you. Fortunately, these programs can be downloaded for free from Web sites like Download.com. Macintosh files are most often "stuffed" into Stuffit files (.sit), which can be "unstuffed" using Aladdin's Stuffit Expander.

The term "Zip" also refers to a product by Iomega. The company makes a removable storage device called a Zip Drive. Depending on the model, these drives can hold 100, 250 or 750 MB Zip disks. They are usually used for backup and for transferring large files to different locations. However, Zip drives are not as fast as hard drives, so it is usually not a good idea to run programs off them.

File extension: .ZIP