There are several different types of operational styles available in modern windows. The choice of which to purchase will depend on several factors. Each operational style has tradeoffs with regards to insulation capacity, ease of operation and price. Your decision will be much clearer once you understand these variants.
Casement windows open with an outward swinging motion.
This style is operated via a crank system allowing them to seal up very tightly when closed. Casement and awning style windows offer some of the best insulation, although they tend to be more expensive than the sliding varieties.
Awning windows are casement windows hung horizontally.
These offer the additional benefit of shielding from the rain when open since they swing upwards and outwards. Like the casements, Awnings seal very tightly but can be expensive.
A fixed window, unlike a casement or awning window, doesn’t open.
From the outside however, it looks basically the same. Fixed sash and picture windows offer the best possible insulation, but can never be opened.
Picture windows, like fixed windows do not open.
They have a smaller frame than fixed style windows giving them a larger glass surface and a less obstructed view. Again these windows provide the optimum insulation at a cost of inoperability.
Single hung windows have a top and bottom sash with the bottom sash able to slide upwards.
Because they don’t seal up as tightly as a casement or awning, and have more seams, sliding windows do not provide as much insulation and draft protection as other varieties. However they can generally be purchased at a cheaper cost.
Double hung windows are much like single hung, except that they have sashes which open from both the top and bottom.
The lower one slides up and the upper one slides down. Again these sliding style windows do not provide the same insulation benifit as the other varieties, but are cheaper to purchase.
Glider windows are also much like sliders. However, they slide horizontally.
Once again, a hit to insulation comes with a more affordable pricetag.
Bay and Bow
Bay and Bow windows are made up of a combination of windows, attached at angles to each other. They extend outward from the wall, providing depth, and a feeling of more open space inside.