An institution is a social structure in which people cooperate and which influences the behavior of people and the way they live.
An institution has a purpose. Institutions are permanent, which means that they do not end when one person is gone. An institution has rules and can enforce rules of human behavior. The word "institution" can be used in two ways. It can mean a very broad idea, or a very "specific" (narrow) one. For example:
Institutions, in the broad sense, are found in every society. The way that each institution works is different in different cultures. Some important institutions are:
Some societies have many institutions in the "specific" sense. These societies have an organised government, schools, hospitals, churches, clubs, armies, markets, courts and places for entertainment. Some societies have very few of these things, but this does not mean that there are no "institutions". The way in which the people relate to each other may have just as many "controls" as in a society with schools, markets and a government. An example of a society that has lots of "specific" institutions is Western Europe.
Historians look at institutions to find differences between eras or periods. They sometimes judge political and military events by the effect that they had on institutions.