One is for small things.
The difference between trees and grains:
When trees and grains are quantifiers, they are different.
"Tree" refers to the number of plants. For example, a tree,
"Star" refers to round or granular things, such as three soybeans and countless stars.
Granular: something granular
Tree: Tree
granule
Quantifier; Mostly used for granular things: a bead | a soybean | a red star.
tree
Quantifier; Mostly used for plants: a tree | a grass.