Welcome to the forums! .tar.bz is simply an archive file format (like .zip in Windows). Anything could be inside the archive: source code for compiling an application, an executable binary, photos of your vacation, etc.
The first step is to unzip the file (most distros have a GUI archive manager for this purpose) and see what's inside. Is there a README file? Can you provide a link to the file/application homepage so we can see exactly what you're trying to install?