There are different types of network devices for different connectivity and are
Hub: It enables PCs to connect to each other by regeneration and passing of network signal on all connected wires and used in ethernet networks. It has one main circuit that all the ports connect to so, total bandwidth of hub, like 10Mbps or 100Mbps, is shared among all PCs connected to it.
Repeater: They extend the signal beyond the standard 100 meters if cable needs to go farther than that. They have two ports, for incoming and for outgoing cable.
Switch: It is like hub, but it takes the signal and sends it to the correct PC linked to it and not to all PCs connected to it as in hub. So, each port has full bandwidth. They have a matrix of wiring instead of a main circuit and logic to pass signal to correct port.
Router: It connects two or more networks and routes data from one location to another, by IP address and IP network numbers. Routers are logical with their own OS, for Cisco device it is IOS (Internetwork Operating System).
Wireless Access Point (WAP): They connect wireless networking connectors on PCs. They transmit data using WiFi standards of 802.11a/b/g/n on 2.4GHz or 5GHz frequencies.
Proxy Server: It works between the network client computers and the Internet. They cache information for clients to increase performance and to conserve Internet connection bandwidth like HTTP proxy. It is on same network as the client computer. To configure PC to use proxy server by; opening Internet Explorer, clicking Tools, Internet Options, selecting the Connections tab, and clicking the LAN settings button then type in the IP address of the proxy server.