What is an archive?
Archives are files that contain other files.
The files in an archive are usually compressed. There are many different types
of archives that have different formats and use different compression algorithms.
Archives make it easy to group files hence allowing for faster and more convenient
transfer. For example, if you wish to send several documents as an e-mail attachment, you can Zip them and send one
archive instead. You will get the benefits of smaller size due to compression and also, easier
handling of one attachment instead of several attachments. PowerZip can create seven different types
of archives - Zip, Tar, Tar.Gz, Tar.Bz2, Arj, Cab and Ha.
What are archives used for?
Most files available on the
Internet are distributed as archives. Two benefits of using archives for online
file distribution are that only one download is required to obtain all related
files, and that file transfer time is minimized because the files in an archive
are compressed.
Another common use of archive is for backup. Compared to hard drives, media used for backup (such as CD-Rs, Zip disks, USB storage devices etc) are typically much smaller so using a compressed archive to save space becomes important.
Some files are important but not used often. To save disk space, these files can be compressed into an archive when they are not used and unzipped only when they are needed.
What is a Self-Extracting Archive?
A self-extracting
archive is an executable program file (.EXE file) that includes both an archive
and software to extract or "unzip" the contents of the archive. Users can
extract the contents of a self-extracting archive by simply running it. This is
convenient, because the end user does not need a compression program (like
PowerZip) to extract files from these self-extracting archives. However,
self-extracting archives have a disadvantage of being larger than the
corresponding zip files because they include the extraction software.
PowerZip can create fully customizable self-extracting archives for Windows. For more information, please click here.
What are the different archive types (formats)?
- Zip is the most common and a very versatile archive format. Unless you have a reason to use another type of archive, Zip is generally a good choice.
- Arj is an older format which has become uncommon. PowerZip needs an external program (arj.exe) to work with Arj files
- Rar is a relatively new archive format developed by Eugene Roshal. PowerZip can extract but cannot create Rar files.
- Tar is a non-compressed archive format popular on UNIX systems. PowerZip can create & extract Tar archives.
- Z, Gz and Bz2 are compressed single-file archive formats used mainly on UNIX systems. Because they can only store one file, they are typically used in conjunction with Tar files - several files are stored in an uncompressed Tar archive which is then compressed into a Z, Gz or Bz2 archive. PowerZip can create Tar.Gz and Tar.Bz2 files. The latter offers better compression but is slower to create and extract than Tar.Gz archives.
- Cab is an archive format developed by Microsoft that is used in many setup programs. PowerZip can create & extract Cab files.
- Ace is a relatively new archive format developed by Marcel Lemke. PowerZip can extract Ace files but cannot create them.
- Ha is an archive format developed by Harri Hirvola. It offers good compression for text files. PowerZip needs an external program (ha.exe) to work with Ha files
- Lzh is an older archive format which has become uncommon. PowerZip needs an external program (lha.exe) to work with Lzh files
- Jar is an archive format used to store Java applications. Jar files are essentially just ordinary Zip files with a different extension (.jar instead of .zip).
All of the above formats are supported by PowerZip.