Software Packaging

Software, both, small utilities as well as comprehensive applications, usually come in so-called software packages which means chunks of bits holding all necessary files to run this particular program. Packages often also contain the necessary libraries (or, at least, references to the latter) to run the executeables.

Historically, most Unix system started with cpio and tar packages which self-contained files are directly written to the respective file system. The shortcoming of either is that they neither care for possibly preinstalled files, nor check whether additional software is needed to run the package.