On 10 Feb 98 at 23:37, Gulraiz wrote:

> Can anyone tell me about zip softwares, what are they and for what
> purposes are they used ? Also what is the function of WinZip and PkZip?

  These programs do two basic things that can help you make more
efficient use of disk space or communications bandwidth:

1.  Compression:  Sometimes the actual information in a file can be
encoded in many fewer bits than the file actually provides.  Text
files are particularly notorious for this, where eight bits are
provided for every character when seven would be more than enough,
and when you take letter frequencies into account, an average of 3-4
bits per character is often sufficient.

2.  Packaging:  A .ZIP file can contain compressed versions of
multiple files, so it wastes no more than a single cluster of disk
space, and can include an error-checking code for each file to verify
successful download/upload.

  PKZIP is the most popular DOS utility to perform these functions,
and WinZip is a Win32 utility that provides compatible functions with
graphical or "wizard" user interfaces.  [WinZip can also decode files
that have been encoded for transmission with UUENCODE or MIME.  These
encodings tend to make files *larger*, but avoid problems encountered
sending certain line characters through certain network systems.]

David G


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