The only difference between the two is the proximity of the devices/networks being connected. A LAN is generally thought of as a single geographic location (such as an office or building). A WAN is a connection between two or more networks that are not closely located to each other. A WAN can be much more expensive to maintain because it often requires either leased or dedicated communication lines between locations, or a high speed internet connection. However, the basic function of both is the same in that they interconnect devices and resources.
 

Normal networking requires only a few key components. In the smallest of environments, only switches/hubs and network interface cards (NIC's) are needed. However, as the size and demands of the network increase, more robust switches and routers may be needed. Most modern computers already come equipped with NIC's, so creating a basic network could be as easy as implementing a single switch/hub.
 

Bandwidth within a LAN is most commonly 10, 100, or 1000Mbps (using the traditional Ethernet standards). It would be very rare that a LAN would operate at a different speed. WAN's, however, are entirely different and bandwidth is determined by the medium in which network segments are connected. Determining how much bandwidth is truly needed in a WAN circuit is dependent on each situation. However, common WAN implementations use T-1 lines (1.5Mbps), T-3 (44Mbps), or cable (3-7Mbps if available). Bandwidth in WAN's can be extremely expensive, so evaluating your needs thoroughly is recommended.
 

Costs are ultimately determined by the size of the network (the number of devices connected to it) and what type of resources are on it. Initial costs can tend to be hefty, but maintenance and administration costs are a lot less. Once implemented, network costs are minimal unless a particular piece of hardware fails and needs to be replaced. Generally speaking, the cost of the network is far less than the cost of doing business without one.
 

They are both pieces of hardware that contain ports for network devices to plug into, thus connecting them and creating a network. However, hubs and switches handle communication differently between the devices they connect. A hub broadcasts all data transmissions to all ports, regardless of which device is the recipient. This limits the overall bandwidth of the network. A switch learns where devices exist on the network and only broadcasts data to the destination port, limiting the amount of traffic to other devices (switches allow for much greater network speeds). Hubs are considered antiquated technology, thus, switches are the new standard.