[shekharbiradar]

Why all moving bodies (winds and ocean currents) move in clockwise direction in Northern Hemisphere and anti-clockwise direction in Southern Hemisphere.

[joypulv]

Actually they aren't all, but the general deflection of wind and water towards one direction or the other is the result of the Coriolis effect, which has to do with how they are viewed from a reference on a rotating body.
Low pressure winds actually rotate the opposite of high in each hemisphere, and the major prevailing winds are west to east nearer the poles and the opposite at middle latitudes, but all are driven by other forces as well as the Coriolis effect, so you see deflection above and below the equator. Water is affected by land barriers, winds, tides, temperatures, and so on, in similar ways.