In marketing, distribution is the process of moving a product from its manufacturing source to its customers. In computer software, distribution is the phase that follows packaging. The package will be on some distribution medium, such as compact disc, or may be simply located on a server where customers can download it electronically.
For open source software such as Linux, companies such as Red Hat and Debian specialize in packaging components from many sources together into a single package or set of packages that can be distributed conveniently to users as a single download. An open source distribution is often called a "distro."