A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model.

Network switches appear nearly identical to network hubs, but a switch generally contains more "intelligence" (and a slightly higher price tag) than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of that packet, and forwarding it appropriately. By delivering each message only to the connected device it was intended for, a network switch conserves network bandwidth and offers generally better performance than a hub.

Routers are physical devices that join multiple wired or wireless networks together. Technically, a wired or wireless router is a Layer 3 gateway, meaning that the wired/wireless router connects networks (as gateways do), and that the router operates at the network layer of the OSI model.

Home networkers often use an Internet Protocol (IP) wired or wireless router, IP being the most common OSI network layer protocol. An IP router such as a DSL or cable modem broadband router joins the home's local area network (LAN) to the wide-area network (WAN) of the Internet.

By maintaining configuration information in a piece of storage called the "routing table," wired or wireless routers also have the ability to filter traffic, either incoming or outgoing, based on the IP addresses of senders and receivers.
Some routers allow the home networker to update the routing table from a Web browser interface. Broadband routers combine the functions of a router with those of a network switch and a firewall in a single unit.

A hub is a small, simple, inexpensive network device that joins multiple computers together.

Most hubs manufactured today support the Ethernet standard. Non-Ethernet hubs (Token Ring, for example) also exist, but Ethernet is always used in home networking. Technically speaking, hubs operate as Layer 2 devices in the OSI model.

To join a group of computers with an Ethernet hub, one connects an Ethernet cable (that has an RJ-45 connector attached) into the hub, then connect the other end of the cable each computer's network interface card (NIC). Hubs also require external power and can be connected to other hubs, switches, or routers.

One good way to differentiate between Ethernet hubs is by the speed (data rate) they support.
The most basic Ethernet hubs support 10 Mbps speeds. Newer hubs support 100 Mbps Ethernet. To help users move ahead to the newer technology while still supporting the old, some hubs support both 10 Mbps and 100 Mbps data rates. These are so-called "dual-speed" or "10/100" hubs.

A common differentiator in hubs is the number of ports they support. Four- and five-port hubs are most common in home networks, but eight- and 16-port hubs can be found in some home and small office environments.