Picture windows, also known as fixed windows, feature fixed glazing installed directly into the window frame and do not open. The name comes from the design providing a picture-like space on a wall and being unable to open. This makes them a popular choice for letting in natural light or creating good views in areas that either do not require opening windows or where it would make little sense (e.g. stairwells, interior areas).
Without a movable sash, fixed glass windows already insulate better than standard casement windows. Therefore, upgrading them with insulated glass in the form of double or triple glazing is a good idea. This allows you to enjoy the increased light and view while increasing thermal insulation, reducing heat loss and saving energy. Further energy efficiency options such as krypton or argon gas filled cavities and special coatings will further boost their u-values.
Stepping back from the idea that all windows must open, it becomes clear that there are far more options for your home design than you perhaps realize. Floor to ceiling windows, skylights, transom windows and more are all typically fixed but provide excellent views, natural light and look good despite not opening.