A chicken coop is a house of some sort built for chickens. Chicken coops need to have nest boxes, perches for roosting, ventilation, and protection from predators and the elements, regardless as to what breeds are within the coop. Chickens have different housing needs depending on the breed. Buckeyes can tolerate significantly colder temperatures than Minorcas, for example. Cold hardy breeds don't need insulation from cold as much as those that are not, while heat hardy breeds need less protection from heat than those that more easily succumb to heat.
In colder climates or areas where temperatures drop to below 0 degrees Celsius a well insulated coop is essential to avoid frostbite.