and it isn't a wireless router, so you can't use it to connect directly to the internet via the phone line or to other computers wirelessly - you'll need to carry on with your normal modem. The router has 4 LAN ports, one of which you connect to a computer with internet access, using a standard Ethernet cable plugged into the computer's network card.
Other computers can be networked via the router in the same way - via Ethernet cables. Each macine will need to have a network card installed of course.
This router was introduced some years ago - 2001 I think - and is looking a bit long in the tooth now, but it should still work well.