The process of rain can be explained by "Water cycle OR Hydrological cycle process".
Because of sun's heat, the water is evaporated into air as vapors and
currents takes water vapors up in atmosphere. As these vapors rises in
air, cooler temperatures cause it to condense into clouds. Air currents move clouds around the globe, cloud particles collide, grow, and fall out of the sky as rain and snow. This
is how we get our rains.
Also view this Graphical representation of How it rains along with this one.
Because of sun's heat, the water is evaporated into air as vapors and
currents takes water vapors up in atmosphere. As these vapors rises in
air, cooler temperatures cause it to condense into clouds. Air currents move clouds around the globe, cloud particles collide, grow, and fall out of the sky as rain and snow. This
is how we get our rains.
Also view this Graphical representation of How it rains along with this one.