As you can see there are many different types of windows out there. There are Double Hung, Single Hung, Casement, Picture, Bay Windows, and that is just to name a few. There are also many different material you can get these windows made out of. There are fiberglass windows, vinyl windows, aluminum windows, wood windows, and some combinations of everything I had just mentioned. All of this can make it very confusing for the average person to know exactly what they are talking about when they decided that their home needs new windows. Because of this there are many homeowners who accidentally buy new windows for their home that might not be the best choice or combination that they could have gone with. There are also many times (which I have seen in my line of work) where a salesman or contractor knows that the person that they are talking to might work behind a desk everyday and does not know much about the industry… and unfortunately more times then not this contractor or salesman might try to take advantage of the average consumer because of their lack of knowledge. Now this gets even more complicated when you factor in the different companies that you can buy windows from. Like any other product in this world, there is high-end, and there is low-end. Some of the high-end window manufacturers out there are Marvin, Pella, Pozzi, and Parrot. Then some of the lower end windows (still perfectly reasonable for the average consumer) would be Anderson, Jeld-Wen, and some smaller and local window operations. So I know I just smacked you with a ton of information overload but hopefully that will be a good start and solid foundation to helo you with your basic understanding of windows.