Re: tarball installtion..................
A tarball is just an archive kind of like a .zip file in Windows. It can contain anything. It may be source code that you need to compile, an install script that you only need to run, or an already compiled binary which you only need to to click to start without doing anything (e.g if you download a tarball for Firefox from Mozilla then all you need to do is to extract it, click on "firefox" without doing anything) The tarball usuallly would come with a readme file that tells you what to do with it.
Usually you don't need to install from source for modern Linux distros, you should try to install from the repositories (using a nice gui frontend like synaptic package manager, which you can install from the Software Centre and then forget about the Software Centre) In Ubuntu there is also an option of adding third party repositories known as PPA (personal package archives?) if you need something not in the official repos or you want an up to date version. The chance that you need to compile from source in Ubuntu is very slim,--though some people like to do it as it gives them more control.
Re: tarball installtion..................
As above.
Also, please do not use all capitals. It is considered shouting. ;)