This document provides information about common networking devices: - A hub physically connects devices on a local area network (LAN) but cannot detect MAC addresses or improve network performance. - A switch can detect specific connected devices by MAC address, perform error checking, and improve network performance compared to a hub. - A router operates at the network layer and is used to connect local area networks, detecting both IP addresses and MAC addresses. - A bridge and repeater both operate at the data link layer, with a bridge able to filter by MAC address and connect two LANs using the same protocol, while a repeater regenerates weak signals on the same network.