A network consists of 2 or more connected computers that can share resources and information. Networks can be classified based on transmission media, size, management method, and topology. Transmission media is the physical path between transmitter and receiver, and includes wired options like twisted pair cable, coaxial cable, and optical fiber cable as well as wireless options like radio waves, microwaves, and infrared waves. Wired transmission media is confined to a pathway using physical links while wireless transmission does not require a physical medium.