From WordNet (r) 1.6 [wn]:

  network
       n 1: an intricately connected system of things or people; "a
            network of spies" or "a web of intrigue" [syn: {web}]
       2: a group of broadcasting stations that all transmit the same
          program simultaneously [syn: {communications network}]
       3: an interconnected or intersecting configuration or system of
          components [syn: {net}, {mesh}, {meshwork}, {reticulation}]
       v : communicate with and within a group; "You have to network if
           you want to get a good job"

This site is on a network and is a network.