Question

Leeward and windward side kya hota ha

Answer 1

In the latter case, the windward side is that side of an island subject to the prevailing wind, and is thus the wetter side (see orographic precipitation). The leeward side is the sideprotected by the elevation of the island from the prevailing wind, and is typically the drier side of an island.

Answer 2

Windward - on the side where rainfall is received 
Leeward - Rain shadow region