The ``traditional'' UNIX way of installing software was to download a source `tarball', untar it (normally 'tar -zxvf foo.tar.gz', or on Solaris 'gunzip -c | tar xv') then configure it (modern software normally automates this via a script you can invoke with ./configure) then compile it with `make' and finally install it (often `make install'). This is quite a lots of hassle, especially if the package is something big and compiling it takes hours. To simplify the process of installing and updating software software `packages' are available for many systems.