What is meant by work in networking field?

i feel a little confused about the meaning of " Networking field " what dose these people do , what is the branches of dis job ? specially in telecom. & carrier companies !!! the only thing i know is that a network is a no. of computers & switches & the wiring between them :D , but i heard that it's more than this like " communication , switches , ADSL , servers , LAN " so can some one make it more simple for me because am studding cicso CCNA now & don't know is that is the right pass or what !!!