Flock is a group of birds. This term is used to describe a group of birds that are flying or feeding together in a relatively compact or cohesive formation. Typically, a flock is made up of individuals from the same species, although mixed-species flocks can occur. Flocking behavior varies depending on the species of bird, with some species, such as geese, forming large, highly synchronized flocks, while others, such as sparrows, may form smaller, looser groups.
The word "flock" can also be used figuratively to refer to a large group of people or things, such as a "flock of people" or a "flock of sheep".