Collective nouns are nouns that are normally in its singular form but that refers to more than one person, animal, thing or concept considered as a single entity because they share one or more characteristic.
"Congregation" is an example of a collective noun because this noun it's singular but it refers to two or more persons organized for some specific purpose.
Some other examples of collective nouns are <em>team, class, herd, flock, gang, mob, group, </em>and<em> family.</em>
