Types of Twisted-Pair Cables

1. A straight-through cable is used when devices at the both end, are not similar in nature of it's operation. for example:
                 a)   from host to a hub (or switch)
                 b)   from a router to a hub (or switch)
The wires on each end of a straight-through cable must be identical. The most common straight-through standard is wired as follows:

2. A cross-over cable is used, when connecting "like" devices. for example:
                          a) a host to a host
                          b) a hub to a hub
                          c) a switch to a switch
To make cross-over cable, we must swap pins 1 and 3, and pins 2 and 6 on the one end of the cable. The most common cross-over standard is as follows:

3. A roll-over cable is used to connect a PC into a Cisco Router's console or auxiliary port The pins are completely reversed on one end to make a rollover cable.

Note:  

1. pins 1, 2 3 and 6 are responsible for transmission of data, rest pins are being used for flow control, congestion control and noise control.
2. Connector RJ45 is used in twisted pair cables.

RJ45

  3. Roll-over cable is used to configure routers.