RJ-45 uses twisted part of different categories. The most common is CAT5E (100MHz, up to 1Gbps when all 4 pairs are used) and CAT6 (250MHz, native 1Gbps). There is a newer standard CAT6A that is even faster.
cat 5 Ethernet cable
crossover cable
ethernet
No. You need to connect the ethernet cable to a modem or router. You can disconnect the PC ethernet cable from the modem and connect an ethernet cable from the Xbox 360 to the modem until you purchase a router.
You do not have to connect your router to your PC via ethernet cable, you can instead connect via wi-fi and your router must be connected to your hub.
You can use any cat 5 ethernet cable to connect the xbox 360 to the router.
You are supposed to connect an ethernet cable from the modem to whatever device that needs an online connection and if you have 2 or more items connect the router to the modem with an ethernet cable and then connect the devices to the router with ethernet cables
Ethernet
To connect to a cisco 1800 series router, you need either a network connection that goes to the router, and then you would configure the router to allow telnet or you would need a console cable, also called a rollover or cisco cable and physical access to the device.
If the wireless router is like mine then you also can make an ethernet connection with the PS3 using an ethernet cable
ethernet cable
Usually with an ethernet cable