Awning Windows

Pros - Awning windows are designed to provide light and breeze. They're great for bedrooms and other areas that need to maintain privacy but still let some light in. Awnings can be opened slightly to allow ventilation. They can be positioned in a variety of places: next to other windows, arranged in columns, or placed above large patio doors to create a wall of light and fresh air.

Cons - Screens for awning windows are set on the inside, which can mean that all the dirt and dust that normally falls into the sash makes its way onto your floors instead.

Casement Windows

Pros - Casement windows open outward for light, fresh air and side breezes. They're tightly sealed for energy efficiency and great for hard-to-reach places, such as over sinks and appliances in the kitchen. Casements crank open, as opposed to sliding up and down, making them easier to maneuver.

Cons - If you're moving into an older home, check on the stability of your casement hinges and hardware. Though casements are usually tough to break into, faulty or rusty hardware increases your risk factor. Consult with a professional for replacement parts or quality new casements.

Double Hung Windows

Pros - Double hung windows are chosen for their unique style, ease of access and superior ventilation capabilities. The top of the window can be opened while the bottom remains closed - great for kids' rooms. Double hung windows can go practically anywhere in your home. They're perfect for kitchens, offices and bedrooms.

Cons - Double hung windows tend to leak more air than other windows. And keep in mind that only half of this window opens up, whereas different types can open completely.

Picture Windows

Pros - Picture windows create unobstructed views of the outdoors. They're best in areas where ventilation isn't a big concern. Think about installing them high on the walls of dark rooms and hallways for infinitely better lighting. In combination with patio doors or open-and-close windows, picture windows bring the perfect balance of light and ventilation.

Cons - These windows are for looks only. And the large expanse of glass can make them more vulnerable to breakage.

Bay Windows

Pros - Bay windows create an open, peaceful feel indoors. Their multiple views allow light to stream in from different angles. Plus, the sides of the window can be opened for air circulation. Bay windows dress up any home with uniqueness and style. Replacing a flat window with a bay can completely change the amount of light that room receives. They're primarily used for kitchens, but can also add character to family rooms and master bedrooms.

Cons - Only the sides of bay windows open and typically don't come with screens, so incoming pests could be a problem.

Jalousie Windows

Jalousies are made of glass slats set in metal clips that can be opened and closed in unison. Also called a louvered window, a jalousie is made like a glass shutter. This type of window is manually rotated to open or close the overlapping panels as required, and can be opened by degrees to control how much air or light passes through. Jalousie windows are best suited for areas with year-round comfortable climates. They help cool a home, but are impossible to seal, making it difficult to keep heat and A/C air inside and extreme weather out.

Hopper Windows

These popular windows are most often installed in basements. The hopper window is basically a casement window flipped on its side. The entire pane tilts inward to open, allowing for maximum ventilation. Hopper windows can make privacy and home decor an issue. Because they tilt into the room, blinds, shades and other window dressings are difficult to use in conjunction with hopper windows. Their tilt designs also makes them a poor choice for ventilation on a rainy day; water will drip right into the room. Also, they're usually placed in basements, so there's an added security risk for any windows installed at ground level.

Here is a good link to find additional detail about windows:
http://ezinearticles.com/?The-Different-Types-of-Doors-and-Windows-in-a-House&id=1691920

Windows can get extremely complex in design, materials used and cost, limited only by ones imagination (and pocketbook).

As technology advances, so will the future in options.

One final note: Windows and Doors accounts for about 30% of the homes energy loss.