Mathematica is symbolic computation software. Use the networked version if you will be installing the software on a computer that is connected to the Carnegie Mellon network.
Mathematica may be installed in either "networked" or "standalone" configurations. The networked configuration requires a connection to the license server operated by Computing Services and your computer must be on the campus network whenever you use Mathematica. The standalone configuration does not require a connection to the license server, but does require you to update the password each year.