opening vs window

opening and window both are nouns.

Word	Noun	Adjective	Verb	Adverb
opening	Yes	Yes	No	No
window	Yes	No	No	No

As nouns, window is a hyponym of opening; that is, window is a word with a more specific, narrower meaning than opening:

opening: a vacant or unobstructed space that is man-made
window: a transparent opening in a vehicle that allow vision out of the sides or back; usually is capable of being opened

As nouns, window is a hyponym of opening; that is, window is a word with a more specific, narrower meaning than opening:

opening (noun)	window (noun)
a recognized sequence of moves at the beginning of a game of chess	a framework of wood or metal that contains a glass windowpane and is built into a wall or roof to admit light or air
the act of opening something	a transparent opening in a vehicle that allow vision out of the sides or back; usually is capable of being opened
becoming open or being made open	a transparent panel (as of an envelope) inserted in an otherwise opaque material
the first of a series of actions	(computer science) a rectangular part of a computer screen that contains a display different from the rest of the screen
a vacant or unobstructed space that is man-made	a pane of glass in a window
an entrance equipped with a hatch; especially a passageway between decks of a ship	an opening in a wall or screen that admits light and air and through which customers can be served
an aperture or hole that opens into a bodily cavity	an opening that resembles a window in appearance or function
a possible alternative	the time period that is considered best for starting or finishing something
the initial part of the introduction
the first performance (as of a theatrical production)
a ceremony accompanying the start of some enterprise
an open or empty space in or between things
opportunity especially for employment or promotion

opening (adjective)	window (adjective)
first or beginning