What is the difference between blunders, mistakes and inaccuracies in chess mean?

My question is in the title

#2 I dont know how stockfish is supposed to reply

An inaccuracy is something you want to avoid. A mistake is something you really want to avoid. A blunder is something you really, really want to avoid.

@Knight04,
Inaccuracy means a good move (not the best); like there could be a better move than what you played; lost forced checkmate sequence, etc.

@FuriousArjun losing forced checkmate sequence is a blunder, not inaccuracy

@PHlinka if you already have a position that is winning for e.g. lichess.org/editor/2k5/4Q3/3K4/8/8/8/8/8_w_-_-_0_1, White plays ...Qd7+, then it is an inaccuracy because after that move it is already checkmate. I mean when you are in a winning position but you delay the check mate by 2-3 moves is inaccuracy.

a blunder should very well be avoided

@FuriousArjun I guess you are right. Still, the move you are describing is not losing forced checkmate sequence, just delaying it