Is there a difference between exterior and interior windows?

There are several differences between an exterior and interior window. However, they are less about appearance and more about function. Both are windows, to be sure, but exterior windows must stand up to the elements and maintain a comfortable indoor environment. Topics like energy efficiency, heat loss and glazing are not important for interior windows, but are essential to purchasing a quality exterior window.  

Interior windows are great for aesthetics and help make a small space feel larger, typically a bathroom or entryway. They are often non-operable and made of wood for aesthetic purposes. Exterior windows can be all that as well, but home comfort and manageable utility bills depend on their level of energy efficiency.  

Interior windows will probably be cheaper as well because vital energy features are unnecessary. Additionally, as more old, wood-framed, single-pane windows are swapped out for newer energy efficient models, there may be a sharp rise in beautiful, vintage wood windows for use indoors.