recipitation occurs when some of the millions of tiny water droplets or ice crystals that constitute a cloud grow large enough and heavy enough to fall to the earth. Rain, hail, sleet, and snow are all forms of precipitation.
Precipitation that reaches the ground in liquid form is often referred to as rain. The lightest form is drizzle, which occurs as fine drops failing closely together. Mist is even finer and does not fall, so therefore is considered a light form of fog.
Precipitation is also classified as intermittent or steady. Usually steady rain and snow fall from clouds such as stratus (flat, layered, low-level) or altostratus (flat, layered, mid-level). Showers or intermittent precipitation will fall from cumulus (blossoming or puffy) clouds.