Microcosm
Etymology
From Greek mikros kosmos, “little world” (mikros, “small,” + kosmos, “world, order”). It grew from the old philosophical idea that a human being is a “little world” reflecting the structure of the universe, the macrocosm. Now it names any small system that mirrors a larger one.
noun · /MY-kruh-koz-um/
A small thing that contains or represents the features of something much larger.
What it names
The small-scale mirror — a single office, town, or family in which you can read the dynamics of a whole society.
Example
The crowded elevator was a microcosm of the company: everyone polite, nobody willing to make eye contact.
Related idea
A macrocosm is its counterpart — the large whole that a microcosm reflects in miniature.