Open by sliding one sash vertically past another.
The double-hung window is the most common style of window available. Most likely, you have seen a double hung window and not even known what it was called: it consists of two window sashes (i.e., panes of glass), one on top, one on the bottom.

The most basic type of window.
A single hung window is the most basic type of window available. The single-hung window consists of a single pane of glass that covers the entire window space and does not move. Consequently, the single-hung window is sometimes called a fixed window.

Open by sliding one sash horizontally past the other.
Pull-out drawers for pots and pans, oversized drawers for baking sheets and designated cabinets for trash and recycling, built-in spice racks, drawer organizers and other cabinet extras will make your kitchen a much more efficient and enjoyable place.

Have a hinge at the side and crank out to open.
Casement windows typically are hinged at the side, sometimes at the top or bottom. They are used singly or in pairs within a common frame, in which case they are hinged on the outside.

Increase the flow of natural light
This type of window projects outward from the main walls of your home, forming a bay in a room, either square or polygonal in plan. The angles most commonly used on the inside corners of the bay are 90, 135 and 150 degrees. Bay windows are often associated with Victorian architecture. They first achieved widespread popularity in the 1870s.

Have a hinge at the top and open outward.
An awning window is a casement window that is hung horizontally, hinged on top, so that it swings outward like an awning.

Are designed for installation of sloped surfaces.
Skylight windows increase natural light in your home. Daylighting is the practice of placing windows, or other openings, and reflective surfaces so that, during the day, natural light provides effective internal illumination. Skylights are one tool of daylighting.

Are stationary windows with curved shapes or angles other than 90°.
Specialty windows not only increase natural lighting, but also provide significant architectural flare.