The windows have to stop the adverse climate impacts to meet our requirements for comfort, to protect us from the cold and keep heat inside that we get from the heating system. They also need to protect us from the summer heat. Which means we need a window as thermal insulator in summer.
Basically according to the material they are made ,windows can be divided into several main groups: wooden windows, PVC windows, aluminum windows (aluminum alloy), wood-aluminum windows. Otherwise there are various metal windows, windows stainless steel, and PVC / ALU windows etc..
There are also bi-fold windows with wide sash frames with bulky hinges and hardware. If you want to provide access between kitchens and patios, or as a corner window to allow increased ventilation, bi-fold window will give you unobstructed panoramic views. This window system is ideal for opening one living area to another. Quality craftsmanship and hardware will provide years of quality use. So if you want to make something new in your home, this is ideal solution. See the following exapmles and get inspiration.