French doors are a popular double door design.  French doors traditional include glass which allows for light to flow thru the space.  

The most common application for French Doors are:

-Patio Doors

-Closet Doors

-Interior Doors

-Modern Doors

-Pantry Doors

Interior French Doors are glass interior doors that are a type of door characterized by multiple glass panels extending for most of their length. They typically come in pairs and are hinged on the sides, allowing them to swing open from the center. French doors originated in France during the Renaissance period and were initially used to allow natural light to enter interior spaces while providing access to gardens or balconies.

Today, they are popular for their elegant appearance and ability to create a seamless transition between indoor and outdoor spaces. They are commonly used as entry doors to patios, gardens, or balconies, as well as between interior rooms to create an open and airy feel.