Many of the files you may want to download from the internet are compressed files. There are a variety of compression formats used. The compressed files on this web site use the "ZIP" file format. A file, such as "xyz.zip" is a compressed file. The compression makes the file smaller, which has the benefit of using less storage space on internet servers and taking less time for you to download to your computer.
Once you have downloaded the file, however, you will have to uncompress it to get the files included back to their original, uncompressed, format. Compressing a file is sometimes referred to as "zipping the file" and uncompressing it as "unzipping". One of the most popular zip programs is called WinZIP and that is used to compress and to uncompress files.
This feature is so prevalent on the internet that the process of zipping and unzipping is built into recent operating systems and some of the internet browsers.
Zipping - On the Mac, if you want to compress a folder called "ExFiles", you would select that folder and then, with a right mouse click, choose the option to "Compress ExFiles". The system automatically creates a file called "ExFiles.zip". On a Windows computer, right-click on a file or folder and then select the option to "Send to > Compressed (zipped) folder." This creates a new .zip file with the same name as the original file or folder.
Unzipping - On the Mac, double-click a zipped file and this creates a folder with the same name with the contents of the zipped file in that folder. On Windows, double-click a zipped file and you see the files in the zip file that you can then drag and drop over to your hard drive or to a USB drive.
Another advantage of zipping being so prevalent on the internet is that we don't have to include lessons here. There are plenty already available on the internet. Below are links to articles and tutorials dealing with file compression. If you are new to the whole process of file compression, you can learn all you need to know. Many of the links below will also provide links to programs you can download to zip or unzip your own files. These are not necessarily the "best" links out there, but they will get you started.
- UCI|EEE Lessons on Zip files -- how to zip or unzip a file on a variety of different platforms.
- ZIP (file format) - this article, from Wikipedia, the free encyclopedia, will provide technical information on the zip file format and it's history, competing compression formats, and links to additional references.
- WinZip - home page for WinZIP, the Compression Utility for Windows. You can try the file out for free or purchase it for $29.95.
- The FreeSite.com - you will find several free utility programs here that you can use to zip and unzip files.
This page updated on June 16, 2021 .