Newby Question

I've always known it as the "Benoni Defence". 

Also, the "Ruy Lopez" sounds much better as "The Spanish Opening", imo.

I also prefer the "King Olaf" to "The Scandinavian."

Some super-old books will say "Benoni Defense", which is very generic.  Most now-a-days list an adjective first to describe the variation, and remove "defense" from it, like "Modern Benoni", "Closed Benoni", "Czech Benoni", etc.  There's even one Benoni line without the word "Benoni" in it, the "Benko Gambit"

Also, no opening is a "White Opening" or "Black Opening".  The opening is the opening, and you play the White side or Black side of it.  The "name", and whether it is attached to "Attack" (typically White), "Counter-Attack" (typically Black), "Opening" (typically White), "Defense" (typically Black), or nothing attached to it (either color) just has to do with which side has made the specific moves that define the position.  Typically the opposing side had numerous options against the defined structure.

Examples:

Torre "Attack" - Defined by White as having played d4, Nf3, and Bg5 (with a Black Knight on f6) is a defined set of moves for White, but this could have been played against 1...d5/2...Nf6, 1...Nf6/2...e6, 1...Nf6/2...g6, etc.  The only thing consistent about Black's position in the "Torre Attack" is that he hasn't played ...f5, and has played ...Nf6 at some point in the first 2 moves.  This is why the opening is named from White's side, White's moves are consisent every time.

King's Indian "Defense" - Again, it's Black's position that is specifically defined, whereas White's position can be anything under the sun that includes d4 and c4.  If you think about the position after White's 5th move in the Classical Variation (5.Nf3), Fianchetto Variation (usually no Nc3 and instead Nf3, g3, and Bg2), Saemisch Variation (5.f3), Four Pawns Attack (5.f4), and many sidelines (5.Ne2, 5.h3, 5.Bd3, etc), in all of these cases, Black has played Nf6/g6/Bg7/d6.  Black has the consistent structure, so the opening would be named based on what Black played.

Catalan, Veresov, etc - Openings without a descriptive word attached to me.  These both happen to be named from White's side, again, due to which side has the consistent moves.

Therefore, openings don't have a name attached from both sides of the board's perspective, but they shouldn't be thought of this way.  Instead of saying "I'm playing the Queen's Gambit because I played d4 and c4 and Black's playing the Nimzo-Indian because he played Nf6 and e6", you wait to see what the third move is from each side, and let's say it's 3.Nf3 b6, then the opening is specifically the "Queen's Indian Defense", and one player is playing the "White side of the Queen's Indian Defense" and the other player is playing the "Black side of the Queen's Indian Defense".

Wow... the pieces are fitting in properly now. 

I was finding a weird pattern too. 

White does the opening move in a game of chess not black. Therefore black has no openings at all. Zero. Only 'defences'.