A classification of cabling according to its physical construction and transmission characteristics. A cable is referred to as “the medium” over which signals can travel in a network. Examples of media include the following:
The term “media” can also refer to a combination of cabling and topology used for different types of Ethernet networks. Thus, for example, 10BaseT refers to a star topology using unshielded twisted-pair (UTP) cabling, while 10Base2 refers to a bus topology using thinnet cabling. You can loosely refer to these examples as 10BaseT and 10Base2 Ethernet media.
Wireless networking uses electromagnetic waves, which are, strictly speaking, not media at all. Wireless networking can be said to use “unguided media.”