Snow is a type of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. (Duh!)
Since snow is composed of small ice particles, it is a granular material. (Not at my house. It's poison!)
It has an open and therefore soft structure, unless packed by external pressure. Snowflakes come in a variety of sizes and shapes. (All of which suck.)
The process of precipitating snow is called snowfall. (Really?)
Snowfall tends to form within regions of upward motion of air around a type of low-pressure system known as an extratropical cyclone. Snow can fall poleward of these systems' associated warm fronts and within their comma head precipitation patterns (called such due to the comma-like shape of the cloud and precipitation pattern around the poleward and west sides of extratropical cyclones).
Oh, yeah? Thanks to Wikipedia for the info, but you know what? Snow just sucks.