Network Interface Card (NIC): In order to connect a computer to a network, that computer needs to have some way of interacting with the network. The best way to do that with Ethernet and Wireless networks is using a Network Interface Card (NIC). A NIC will allow a computer to send and receive electrical or radio signals in a manner that other computers can understand.

Most modern computers come with Ethernet NICs installed by default. Laptops usually even come with Wireless NICs. If your computer doesn’t already have one, you can purchase one from your local computer supply store. They tend to be fairly inexpensive PCI cards. Before you buy a NIC, make sure you know whether you’re going to make a Wireless or Ethernet network.

Cat-5 Cable: Different forms of networks use different mediums to talk amongst the computers. In a network that is mostly wired, Ethernet cables allow the transmission of data from one networked device to another. Category-5 (Cat-5) cable is one of the most common types of Ethernet cable. When connecting computers to a network, one end of the Cat-5 cable is plugged into the computer’s NIC and the other is plugged into the hub, switch, or router.

It looks something like a very thick phone cord with wider than normal plugs on the ends. Technically, Cat-5 (and all other Ethernet cables) is twisted pair wire. Each Cat-5 cable has 4 pairs of wires in it that are terminated at the plug.

Hub: In order to connect more than two computers together, a device that distributes packets must be used. A hub is the most basic of these devices. When a computer connected to a hub makes a request for data from another computer, that request will be sent to the hub. The hub will then send that request to every single computer it’s connected to, including the originating computer. Most of the computers on the network will ignore the request. The computer that the request is being sent to will accept the packet and send out a reply packet. The reply packet will again be sent to every computer by the hub.

As you can see, hubs are very inefficient. One of the problems with hubs is that they often cause collisions. Collisions occur when a computer is trying to send a packet when the hub is sending its own packet. The packets “collide” and the data from both of them must be resent.

Switch: Switches are much more efficient than hubs. They work in much the same as hubs do, but they keep a list of all computers connected to them. When the switch receives a packet, it can send the packet directly to its destination by comparing the address on the packet with the switch’s list.

Router: A router is a device that will join two different networks together. Home networks usually employ routers to connect to the Internet. The majority of routers commercially available contain a switch within them. All of the computers on the network can communicate as usual. When they attempt to access the Internet, the router will redirect the local area network traffic to the second network it is connected to.

Modem: Modems are devices that allow you to connect to your Internet Service Provider and browse the Internet. Because modems only provide one IP address each, the best way to use a high-speed modem is to share its services among computers.