Types of Doors

Tips from Real-Estate-Agents.com

A door's function determines its construction, appearance, and operation. If it's meant for security, it features solid, durable construction and highly effective hardware. If, in addition to providing access, it's intended to permit natural light or views, it incorporates glass, a French door or glass slider, for example. If ventilation is important, the door may have a louvered construction or a portion that swings open, like the half-acting Dutch door. For dividing rooms, a lightweight, economical hollow-core door is often preferred.

Doors are also distinguished by their action. Although most swing on hinges, some slide along tracks or fold and unfold.
Exterior sliders operate easily, seal out the weather, and admit plenty of light. Folding doors are often used to conceal a wide space where a conventional door's swing would be cumbersome or restricted.
Bypass doors, often used on closets or storage areas, are lightweight indoor sliders that hang from rollers that run along an overhead track. They're typically mounted in pairs or threes; they bypass one another to allow access.
A pocket door is another type of slider that is ideal for places where there isn't room for a door to swing. It slides into a space or "pocket" installed in the wall.
Most doors are designed to look like wood. Materials such as steel and fiberglass can simulate the look of wood and are more affordable, have a greater insulation value, and require less maintenance.
-- Tips courtesy of Service Magic