Q. What are the major difference between four wheel and two wheel drive and what is the effect - Pajero Sport?

In a two wheel drive power is transferred from the engine to two wheels only whereas the other two are free. In a 4X4 vehicle the power is transferred to all the four vehicle giving it much better traction and even if two of its wheels are slipping the other two wheels will pull the vehicle out of any tricky situation like snow, mud or sand. I have 2 wheel drive vehicles failing on steep inclines whereas a 4 wheel drive vehicle like my Pajerosport tackled it very easily.

Most of the times 2 wheel drive is sufficient, 4 wheel drive is required in difficult driving conditions like, Snow, Mud, Sand etc. In 4 wheel drive engine power is transferred to all the 4 wheels.