Most all homes are equipped with multiple vents. You will find them on the underside of your soffits and you will have one on a gable end. Some older homes may not have gable vents because building code standards at the time the house was built were not as strict as they are now.
A gable vent is typically found on the end of a house, over the garage. A gable is the portion of a house that comes to a peak. Many homes will have multiple gables and some have multiple gable vents.
A gable vent comes in different sizes and shapes, depending on the builder and the design of the home.
The gable vents found on the average home are made out of wood and have screen wire backing.
A gable vent is designed to allow hot air to escape from the attic. Attics become extremely hot in the summer and a way is needed for that air to escape.
Without gable vents, attics are a potential source for fires if there is no way for constant extreme heat to escape.