Precipitation refers to any form of water that falls from the sky.   It can be measured using a simple rain gauge.  No matter what type of precipitation that you are talking about, it all starts with the condensation nuclei.

	the size of the condensation nuclei determines the size of the initial droplet
	larger droplets capture smaller droplets on the way down
	the longer the droplet is in the cloud the larger it grows

The type precipitation depends on the conditions surrounding its formation and delivery.

	separated by size
	rain = > 0.5mm & drizzle < 0.5mm
	freezing rain occurs when rain is super-cooled on the way to Earth and freezes on contact with Earth's surface

	Higher altitude rain falls through a lower freezing layer of air
	Forms into ice crystals before reaching Earth's surface

	Forms much the same way as sleet
	is kept aloft by wind as it accumulates more frozen water mass
	falls to the ground once its mass is heavier than the force of the air currents

usually 1-5cm in diameter (13.97 cm is largest on record)

is an aggregate of ice crystals that does not thaw on its way to Earth's surface