RJ45 cable is used widely in computer network. Straight connection is used to connect two different devices example computer-modem, computer-printer, computer-switch, etc. Cross connection is used to connect same type of devices example computer-computer, switch-switch, etc. Follow this Wikipedia link to know more about crossover cable. Crossover cable can be used to form network of 2 computers.
RJ45 cable has 8 leads, as EIA/TIA 568B standard colours of wires are fixed as
For straight connection both side have same order as specified, for cross connection one side should be EIA/TIA 568B standard and
other side should have interchanged order. Connect the wire as shown....
You can use RJ45 EIA/TIA 568A standard cable also, only difference is colour.
Get RJ45 pin from local computer shop, get 1.5m of RJ45 cable and crimper.