Although each archive basically contains collections of files and folders inside them, exactly how they contain these files and folders may change. The details are technical, but what changes between different archive types are:
Compression: Different archive types have different compression algorithms. The same collection of files and folders, compressed with different archive types, can result in smaller or bigger archives, depending on the strength of compression. Also, the speed of compression varies between different archive types.
Storage: Some archive types can contain only a single file. Other archive types can contain multiple files, and even multiple folders.
Other: Archive types may have many other different properties. For instance, some archives types support comments, explaining what is contained in the archive.
Archive types are typically identified by their file extensions, rather than the name of the compression algorithm they use. Some of the popular archive types available today, by file extension, are described below:
ZIP: The most popular archive type available today. This is a very old archive type and is supported on virtually on all computer and operating systems. The compression strength is by now considered weak.
JAR: JAR archives are virtually identical to ZIP archives. JAR archives were created by SUN Microsystems and are generally used with Java software.
RAR: Another classic archive type, which is also very popular. The latest upgrades to this archive type have dramatically increased compression rates!
ACE: A relatively new archive type, gaining in popularity. This archive type also supports very good compression rates!
CAB: The archive type developed in 1997 by Microsoft. Provides good compression ratios and very fast extraction speeds. Until recently, CAB was the strongest compression available; however upgrades to the RAR and ACE formats have dethroned CAB as the strongest compression format.
7-Zip: A brand new compression type! 7Z archives feature the best compression available today, with highly sophisticated compression algorithms.
TAR: This archive type is primarily used on UNIX/Linux systems. It does not actually compress files and folders it contains at all, but just packs them into a single file for further compression.
GZIP: This archive type is primarily used on UNIX/Linux systems. GZIP archives may contain only a single file. Because of this reason, GZIP archives generally contain TAR archives, which contain multiple files and folders.
BZIP2: Similar to GZIP, but with greatly enhanced compression ratios.
CompreXX mark4 fully supports all of the above archive types internally - without requiring any external programs!
See also: