A network switch or switching hub is a computer networking device that connects network segments. The term commonly refers to a network bridge that processes and routes data at the data link layer (layer 2) of the OSI model. Switches that additionally process data at the network layer (layer 3 and above) are often referred to as Layer 3 switches or multilayer switches. The term network switch does not generally encompass unintelligent or passive network devices such as hubs and repeaters. To understand basic networking, you first need to answer the question, "What is a network switch?" Most business networks today use switches to connect computers, printers and servers within a building or campus. A switch serves as a controller, enabling networked devices to talk to each other efficiently. Through information sharing and resource allocation, switches save businesses money and increase employee productivity. What is a Network Switch versus a Router? Switches create a network. Routers connect networks. A router links computers to the Internet, so users can share the connection. A router acts as a dispatcher, choosing the best path for information to travel so it's received quickly. Buying a switch is not as simple as walking into a store and grabbing one off the shelf. When I’m purchasing network equipment or giving advice to others on what they should buy, I like to look a couple of years down the road. Will your network increase significantly in size? Will you be adding devices to your network? A quick look at the future can help you decide what type of switch to buy. There are a number of specifications that determine how good the switch really is. Count the number of network devices that need physical connection to the switch. Such as network printer, computer, IP camera, etc. Mid level switch normally has 24 ports. Stacked more than one switch if you need more ports. Are you required high speed network? Normal switch still use 100Mbps port, where higher end switch support 1Gbps. It depends on your cable and device NIC too. Gigabit Ethernet LAN switch is important for applications that use video, voice or complex digital images. Some enterprise-class switches support 10 Gigabit ports for larger networks and high speed demanding applications such as such as video broadcasting, digital imaging, real-time financial transactions, etc. Power over Ethernet or PoE is able to supply electrical power through the LAN cable to the attached devices. Hence save your power extension cost. PoE switch is useful for devices such as wireless access points (WAP), IP security cameras and IP phones. Choose any other features that you may desire. There are many other features that switches often have that may need to be factored into your decision: whether the switch is managed or unmanaged, how to access its configuration interface (if it is managed), whether it is a layer 3 capable switch or not, and many others. These features are mostly only useful in larger enterprise networks; if you are building a large network, it's a good idea to research what some of these additional features can do for you. Pick a vendor and/or company. Chances are that you will not be buying directly from a manufacturer of network switches, however you may prefer one brand over another. Popular brands of networking equipment include Cisco, 3com, Juniper, HP and Nortel. Smaller switches can often be found at major retailers such as Wal-Mart, Radio Shack, and Best Buy, while larger ones are more often found online. Best Buy does sometimes stock up to 24 port switches, but for larger switches online retailers may be a better choice. Baynetwork.com and CDW.com are excellent websites for researching and buying network hardware.