Mostly because of security issues and EMI.
because it is . ;)
Wired networks have a wire that connects them to an internet port, wireLESS networks do not.
No, wireless networks tend to be slower than wired networks but they offer more range and you don't need a whole lot of wires. Wireless routers normally have Ethernet ports so you can have a mix of wired and wireless if you desire. The speed difference between the two is barely noticeable, well that's my opinion.
wifi
False.
Ethernet is a wired networking solution. Even thou WiFi resembles a lot of the key distinguishing features of Ethernet, Ethernet is clearly defined as wired by IEEE (Protocol 802.3) while WiFi is defined as wireless (Protocol 802.11).
Wireless or Wired (ethernet cable).
Wireless networks are not laid out using the same topologies as wired networks. They have their own, different layouts. Smaller wireless networks, in which a small number of nodes closely positioned need to exchange data, can be arranged in an ad hoc fashion.
Modem.
Yes the switch is called a router and it can be wireless or wired with ethernet cables. I use my wireless router as a wired router because it also includes four ethernet cable connections in the back.
It's supposed to, but the problem with wireless networks that you can catch packets even if it was not send for you. Such problem was eliminated for wired networks a while ago, the solution is used in all routers. For wireless networks such solution cannot work in principle.
Wired networks, also commonly known as Ethernet networks, are the easiest and most reliable way to connect your computer to a network. Windows XP automatically configures wired networks, and all you need to do is connect your computer to your network equipment using a network cable.