窓枠 and 天窓: a window frame and a skylight
Distinguish 窓枠 as a window part from 天窓 as a type of window, following the frame's color and partial condition and the skylight's light and ventilation examples.
窓枠 names a part: the window frame
「木製の窓枠を白く塗り直した。」 describes repainting a wooden window frame white. 窓枠 is the frame, 木製 specifies its material, and 白く gives the color applied to that frame.
「雨で窓枠の一部が腐っていた。」 says that part of the window frame had rotted because of rain. 一部 limits the condition to part of the frame. It does not say that the entire frame or whole window had rotted.
天窓 names a type: the skylight
「天窓から朝の光が差し込んだ。」 says that morning sunlight came through a skylight. 天窓 names the type of window, and から marks the path by which the light entered.
「屋根裏部屋の天窓を開けて空気を入れ替えた。」 describes opening the attic skylight for ventilation. Opening the skylight is linked to changing the air in this example; it does not set an installation purpose or lighting standard for all skylights.
Keep the part and type relationships distinct
窓枠 and 天窓 are not two names for different window types. 窓枠 names the frame, a part of a window; 天窓 names a skylight, a type of window. Establish that relationship before attaching color, condition, light, or ventilation details.
White describes the repainted frame, and rot affects part of the frame. Morning light comes through the skylight, and the attic skylight is opened for ventilation. These details do not determine the color or condition of the whole window or house.
Are 窓枠 and 天窓 two types of window, or do they name a window part and a window type?
Show the answer and why
窓枠 names the frame, a part of a window, while 天窓 names a skylight, a type of window. White paint and partial rot concern the frame; incoming light and attic ventilation belong to the skylight examples. Damage to part of the frame does not establish damage to the whole window.