comparative form of small: more small
"The puppy is smaller than the dog next to it."
In plain English: Smaller means being less big than something else.
"The smaller room was filled with sunlight."
Usage: Use smaller to compare two items by indicating that one has less size, extent, or amount than the other. It is always placed before a noun as an adjective and never used after it like larger forms such as "the bigger."
comparative form of small: more small
"The puppy was smaller than its older brother, making it easy for him to fit in a tiny carrier."
In plain English: Smaller means to make something less big or less important than it was before.
"The car is smaller to fit in tight parking spaces."
Smaller is the comparative form of small, which derives from Old English smæl meaning narrow or slender. It retains this sense of reduced size in Modern English through its Germanic roots.