Compressing a file means using special mathematical algorithm to replace repeating pieces of information with shorter ones, to reduce the size of the file being compressed. Once compressed it cannot be used as normal file until it is decompressed. There are many different algorithms and software programs used to achieve file shrinking, with most important and famous ones being Zip and Rar for Windows environment, and GZip and Tar for Linux environment. Included in most versions of Windows is the Zip algorithm, and as it is fully integrated, you can work with compressed files and folders almost as with normal ones.
How to do it, and some compression issues
Thanks to the full integration of zip algorithm in Windows Explorer it is extremely easy to use it. To compress a folder or file in Windows 7, just select it, and right-click. Select “Send to”, then click “Compressed (zipped) folder”. A new, compressed, folder is created in the location you are in, and you are done. You can rename it the way you want. You can enter it and view files in real-time, just like you would in normal uncompressed folder. You can add files or folders to already compressed folder by just dragging and dropping them.
To uncompress files or folders from the compressed folder, just select them and drag them to a location you want to extract to. Yes, simple as that. Another option is to extract all files and folders at once – right-click the compressed folder and select “Extract all”, select the location from the menu which will be shown, and click “Extract.”
When you use compression, always remember that if you put encrypted with Windows 7 files into an archive, encryption is lost. This is huge privacy risk, so be careful. Also, some formats are already highly compressed, and there is no use to compress further, some of these are .jpg pictures, most .avi movie files and .mp3 music. If you compress such file, sometimes the resulting compressed file is not smaller, but bigger than the original – useless.