Investigation should include the

definition of a network—connecting two or more computers together for the purpose of sharing information and resources
development of the first network (e.g., 1975—first transmission control protocol/Internet protocol [TCP/IP] tested)
types of networks (e.g., local area networks [LANs], wide-area networks [WANs], personal-area networks [PANs], campus-area networks [CANs], metropolitan-area networks [MANs])
networking terminology (e.g., Internet, intranet, traffic, gateway, IP address, terminator, hub or concentrator, token, signal bounce, bridge, router, server, virtual private networks [VPNs], crosstalk)
trends related to networking, such as the use of wireless technology.