Definition of File Compression
Advances in technology make information sharing common and convenient for both business and home computer users. You can transfer files containing text, images and even entire project presentations for others to view, edit, store and send to other users. Problems can occur, however, when large file sizes eat away at available hard drive space and create bottlenecks in computer networks. File compression is a process that uses a software program to make large files easier to store and transmit.
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Identification
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File compression software can accept one or more related files, combine them and reduce their size to make them more suitable for storage or transmission. Archiving is the term generally used when compressing files for storage, but the idea is the same as for file transfer. File compression eliminates data redundancy, using an algorithm that locates repeating patterns of the binary numbers zero (0) and one (1). The more repeating patterns compression software can find and eliminate, the greater the compression.
Lossless Compression
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Lossless file compression uses a process that results in no loss of data. The file size you start with is the file size you end with when you decompress the file. An example of a lossless compression method is the LZW method, named after its creators, Abraham Lempel, Jakob Ziv and Terry Welch. The LZW method uses an algorithm that remembers, stores and references repetitive pattern information in a built-in data dictionary. This method is efficient for files containing repetitive information, such as text, or monochrome image files, such as GIF (Graphical Interchange Format) or TIFF (Tagged Image File Format) files.
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Lossy Compression
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Lossy file compression results in smaller file sizes that do not fully restore when decompressed. Data may change somewhat, or be missing altogether, but not with enough significance to be noticeable unless the same file undergoes compression numerous times. Lossy compression methods go by the name “codec,” with the purpose of the program being to encode and decode digital data. Examples of files suitable for lossy compression include streaming media, audio files and image files such as JPEG (Joint Photographic Experts Group) or PNG (Portable Network Graphics) files.
Tools
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You can find file compression software tools available for purchase, free download and sometimes included as a feature with your operating system. Compression tools available for purchase include programs such as WinZip, WinRAR and Stuffit. Programs you can download and use free include 7-Zip, ZipGenius and SimplyZip. Windows XP, Vista and Windows 7 contain a basic, built-in zip feature you can use for simple file compression or decompression tasks.
Significance
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File compression software is a tool that makes data transmission more convenient and less expensive. Because you have the option to package and compress related files together, transmission becomes less time consuming and more organized. File compression can save both the business and home computer user money by conserving hard drive space and Internet bandwidth, and by reducing the number of CDs or DVDs required for transferring or storing media such as music or photos.
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