Google for window images, and you'll see that you can make a career out of creating windows, plain and fancy.

Glazing Patterns	A picture window may have one large pane of glass, but many small, square panes (six, nine, or twelve) suggest Colonial, Georgian, or Federal. The strips holding the panes together are called muntin. A sash consists of a number of panes.   The Tudor, English cottage, and some Mission-style homes often use diamond panes.   Leaded glass can be very ornamental and is often found in Victorian windows. Generally they're fixed windows that don't open.   Not all windows are created square or rectangular. It can be shaped like an arch with a pointed top, commonly found on Victorian Gothic houses. It can be a rounded arch found on Italian Renaissance and Victorian Italianate homes, or semi-circular (Federal or Adamesque).   Consider the Palladian window, named after the Renaissance architect Palladio and found on Federal, Queen Anne, and Classical buildings. It's divided into three parts: a wide arch flanked by two rectangular panes.   There are triangular and trapezoidal windows. A gambrel window follows the line of a gambrel roof.
Window Locations	Fanlights, which are semicircular, may be found above the entry door in Federal/Adamesque buildings.   Sidelights are tall narrow windows flanking the entry door in Greek Revival homes.   Ribbon windows are common in Prairie, Craftsman, and 20th century homes. They're place in a row, one against the other.   Although bay windows jutting out from the side originated during Medieval times, they are very popular on Victorian houses.   A bow window is essentially a bay window made with curved glass or three or more sections of glass. It juts out from a wall.   An oriel window is supported by decorative brackets or corbels and juts out from an upper storey. Found in Gothic Revival. The clerestory is a wall of a room or building that rises above the roof and contains windows.
How Windows Work	Many ornamental windows are fixed.   A double-hung or Georgian window has sashes that slide up and down. In a single-hung window, only the lower sash moves.   A contemporary traverse window slides back and forth like a patio door.   A casement window (Craftsman, Tudor, Mission, for example) is hinged on the side and opens with a crank. If you put two side by side, you have a French window.   If you have a window hinged at the top, opening out, it's an awning window. If it opens into the room, it's a transom, but if it's hinged at the bottom and opens into the room, it's a hopper or eyebrow window.   A jalousie or louvers functions like Venitian blinds with glass slats that crank open and closed. European tilt-turn windows can be turned for each cleaning. They tilt from the top.