Definition: – ACompression Program is a software program that is used to compress ordecompress files. Most often such a software program is used to compress filesof various formats that are no longer being actively used and reduce their sizeso that they take up about 40 percent less space on hard disk. However, a filecompression utility is used in many other situations, for example where largesized files of one particular format need to be compressed. Here it can be usedwhen thousands of files of one format are created on a daily basis and theseneed to be compressed. For instance, when image files are created as part of ascanning process, such a software program can be used to convert these normallylarge sized files into much smaller ones. This can result in a large amount ofdisc space being saved as such files can quickly overwhelm servers, especiallywhen a scanning process is continuous and files are created daily.
A) Compression programs that are associated with following fileextensions: – · .ZIPMAC: – Smith Micro Stuffit Deluxe, The Unarchiver, Apple ArchiveUtility, Incredible Bee Archiver.Windows: – WinRAR, Smith Micro StuffIt Deluxe, 7-Zip.
· .SitMAC: – Smith Micro Stuffit Deluxe,Incredible Bee Archiver, The Unarchiver. Windows: – Smith Micro StuffitDeluxe, Extract Now. · .SitxMAC: – Smith Micro StuffIt Deluxe,Incredible Bee Archiver, The Unarchiver. Windows: – Smith Micro StuffIt Deluxe.
· .exeMAC: – Parallels Desktop for MAC withMicrosoft Windows, VMware fusion with Microsoft Windows installed, Oracle VMvirtual Box with Microsoft Windows installed. Windows: – Smith Micro StuffItDeluxe. B) Extensions which represent a self-extracting format· .zip· .
exe C) Extensions associated when we use Windows or MAC “.sit”,”.sitx”, “.zip” are all three associated with both Windows and MAC OS. But”.exe” is not executable on MAC OS. There must be Windows OS inside MAC OS torun “.
exe” extension files. D) Comparison of Compression program ZIP and RARare two different formats. Both use LZ77, which replaces duplicate strings withpointers to the previous occurrence. However, RAR usually compresses better (atthe cost of more memory) by using a larger sliding window so it is able topoint to older references. Anotherdifference is that ZIP is an open format but RAR is proprietary. ZIPcompressors are free and open source. The RAR decompressor (unrar) is free, butthe compressor is not.
E) Summary From this we learned aboutcompression programs and different types of file extensions. File compression reduces the amountof space needed to store data. Using compressed files can free up valuablespace on a hard drive, or a web server. Some files, like word files, can becompressed to 90 percent of their original size.
Other files, like JPEG or MP3files, cannot be compressed further since these types of files are alreadycompressed.