This is the 16823rd most frequent Russian word.
снежок
A small ball of snow or light snowfall.
The word 'снежок' here refers to light snowfall.
На улице начал падать лёгкий снежок.
A light snow began to fall outside.
Here, 'снежки' (plural of 'снежок') refers to snowballs made for playing.
Дети играли на улице, кидая снежки друг в друга.
Children were playing outside, throwing snowballs at each other.
In this context, 'снежок' is used poetically to describe the covering of snow on the ground.