Epitome
Etymology
From Greek epitomē, “abridgment, summary,” from epitemnein, “to cut short” (epi-, “into,” + temnein, “to cut”). It first meant a condensed summary of a longer text; from “the essence boiled down” it came to mean a person or thing that concentrates the defining nature of a class.
noun · /ih-PIT-uh-mee/
A perfect example that embodies the essential qualities of something.
What it names
The single instance so representative it can stand in for the whole category — the thing you point to when you mean “this is exactly what that is.”
Example
The corner diner, with its chrome stools and endless coffee, was the epitome of a certain American ideal.
Related idea
An epitome is a concrete example that embodies a type; quintessence is the abstract purest essence itself that such an example embodies.