What's the difference between door and quadrivalve?

Door

Definition:

(n.) An opening in the wall of a house or of an apartment, by which to go in and out; an entrance way.
(n.) The frame or barrier of boards, or other material, usually turning on hinges, by which an entrance way into a house or apartment is closed and opened.
(n.) Passage; means of approach or access.
(n.) An entrance way, but taken in the sense of the house or apartment to which it leads.

Example Sentences:

(1) We were instantly refused entrance by the heavies at the door.
(2) He can open doors anywhere and they would at least have someone else to blame.
(3) The only other black woman I see in the building: washing dishes behind a door that was supposed to have been locked.
(4) Macy’s said more than 15,000 people were lined up outside its flagship New York City store when it opened its doors at 6pm on Thanksgiving.
(5) Clifford began representing the family after the media were "camped out on their door" earlier this year but said that he was not being paid by the family, added that the story should never have been in the paper.
(6) America is made up of immigrants and to shut the doors to others is just ludicrous.
(7) Another source inside the centre, quoted earlier on the Detained Voices blog, said detainees had banged on their doors throughout the lockdown.
(8) It's not good enough for some councils to respond to funding problems by cutting care behind closed doors.
(9) It was also chided for failing to roll out a 2011 pilot scheme to put doors on fridges in its stores.
(10) Back then, before her life took a darker turn, Holiday was able to leave the song, and its politics, at the door on the way out.
(11) Criminal court charges leave me no choice but to resign as a magistrate Read more “This is a terrible piece of legislation introduced through the back door,” he wrote.
(12) One day, out of the blue, there's a knock on the door.
(13) Attach self-adhesive foam strips, or metal strips with brushes or wipers attached, to window, door and loft-hatch frames (if you have sash windows, it's better to ask a professional to do it).
(14) At 7.40am Lord Feldman, the Conservative party chairman, knocked on the front door of No 10.
(15) The case of a 32-year-old man who suffered a blow to his left supraorbital region and eyebrow in an automatic closing door is reported to draw attention to the uncommon but trivial nature of this injury which may result in profound visual loss.
(16) A family who live next door to the Bredon Croft address said Masood used to turn up in Islamic dress and take their neighbours’ children to a mosque, though they did not know which one.
(17) I'm concerned, because it opens the door to all sorts of people with opinions that aren't sensible.
(18) This is done by scoring the septal cartilage in its basal attachment to the maxillary crest, providing a "swinging door" which can be sutured finally as desired.
(19) Matteo Renzi, the Italian leader who has argued it would be a disaster if Britain left the EU, suggested defensiveness about freedom of movement led to nowhere apart from opening the door to “right-wing xenophobia and nationalism” in Europe .
(20) She told Time magazine that “doors and windows were flying” after the blast.