Definition & Meaning of "little frog in a big pond"

What is the origin of the idiom "little frog in a big pond" and when to use it?

The idiom "little frog in a big pond" is a figurative expression used to describe someone who feels insignificant or out of their depth in a larger or more competitive environment. The origin of this idiom is not well-documented, but it likely emerged from the observation of small frogs in large ponds or bodies of water where they might seem inconspicuous and vulnerable compared to their surroundings. It is often used to convey a sense of insecurity or discomfort in unfamiliar or overwhelming situations.