A straight cable is used to connect a PC to a hub, switch, or router.
Routers connect via your computer's ethernet input.
Depends on how many switches each router takes. You need a router to connect all the other routers, and then enough switches to make 81. For example, you can use 6 16 port routers to connect the computers and 1 8 port router to connect those routers together
Most wireless routers also allow you to plug in 4 to 8 other Ethernet cables. It would not be a router otherwise, it would simply be a wireless access point. The cable connections are also faster than the wireless (at this point).
I'm pretty sure LAN's are a group of computers connected to each other through routers/modems or ethernet cables. The internet it similar to LAN's but instead of connecting to other computers close by, it connects to computers all around the world.
Ethernet switches can be used instead of routers to connect computers to the internet. There are several products available. The Netgear FS605 will link up to five computers or devices to the home's online network. The Linksys EZXS55W is another model that can link up to five devices and has the advantage of being compact.
Straight through cables can be used to connect devices together via switches, hubs, routers, bridges.
All routers perform the same action. They allow you to hook up multipule computers, and also giving your network security. Many people debate between which routers work better, and which have more reliability, i would recommend researching online and find some reviews. Routers do not "power" computers. There is a technology called power over ethernet but it's generally used for network attached storage devices or routers rather than "computers."
Wireless routers have spots on the back to plug in ethernet cables. Mine has one input and 4 outputs. It may work if you plug in one wireless router to your modem and then run the ethernet cable from the out of that wireless modem to the in on the other
Ethernet cable is used in any length to establish physical network connectivity between Ethernet compatible devices such as computers, routers, printers and entertainment devices. Cable networks are utilized when there is a need for security (laboratories), no practical use for external access(LAN parties), or to connect to internet capable nodes such as wireless routers and modems. A 100 ft cable might be used to connect a wireless router in your garage to the internet connected network in your home, expanding your personal wireless hot spot.
You need a crossover cable to connect two routers via normal Ethernet interfaces.
Routers, Switches, Modems, and Hubs, but mostly Routers
Many Wireless routers and switches have few inbuilt switching ports capable of connecting Wired computers to Wireless Computers on the same network to connect wired Computers also alongwith. (Not necessarily every every wireless router will be having switching ports)