beginner chess terminology: opening is white's and defense is black's? absolute beginning self-learner here, asking trivial terminology:
xyz(placeholder) opening is speaking of white's play and zyx(placeholder) defense is referring to black's play, is that correct?
or
opening schemes are played by white, while defense schemes are played by opponent -- the black.
Is this thinking correct?
I believe that there is not much meaning in these terms and the terminology developed historically. Terms like opening, defense, attack, game,... are often used synonymously.

Opening is the general term which can be used to refer to any sequence of moves at the start of the game. 

Also it refers to systems that develop after 1. e4 e5 (e.g. Italian, Spanish openings) which a long time ago were by far the most popular and considered the best because they follow the straightforward plan of occupying the center and developing pieces to active positions. 

Later, other openings were developed which do not follow such a natural plan. E.g. in those new openings white is often allowed to create a strong  pawn center which black later attacks. Many of these received the name defense, perhaps to signify that black is not going for active play immediately but lets white get somewhat active. Examples are the French, Sicilian, Caro-Kan, King's Indian,... defense.

However note that in these defenses it is black who determines the structure of the game to a large extend, by deciding e.g. between the French or the Sicilian which result in completely different kind of games. In the Spanish/Italian on the other hand it is white  who makes the major decision on the third move, between 3. Bc4 and 3. Bb5.

Then there are also the attacks (e.g. King's Indian attack) which often refer to color-reversed defenses. In these it is mostly white who decides the structure.

Generally (with a few exceptions, usually called "system" or "set-up" such as the Colle system), black's and white's moves in openings are related. So it does generally not make sense to talk about an opening for one side only. For instance the King's Indian is basically defined by a certain set-up for black: (pawns on d6, e5, g6, bishop on g7, short castle, later play f5 and attack on the king side). But still experience has shown that there is a recommended way for white to play against it and therefore King's Indian means both, the black and the white set-up.

But as mentioned, don't break your head over this. Just take it as a name without much meaning. In the same way there is not much meaning in "open", "semi-open", "closed" openings. For instance you can have very closed positional play in some lines of the Spanish/Ruy-Lopez which would be classified as "open".

If you are a beginner focus on general opening principles and tactics. This will be more useful than learning a specific opening.