When the temperature in the atmosphere falls below the freezing point, the water vapour directly turns into snowflakes. This is called sublimation.
Here, the vapour in the form of gas transforms into solid snow.
Precipitation in the form of solid particles is known as snowfall.
In high latitudinal and temperate regions, snowfall occurs at the mean sea level while in tropical areas, snowfall occurs at places located higher than the snowline altitude.