What is the difference between missed win and blunder

Sometimes, when I may capture the queen, but I retreat this is counted as "Missed Win".
If pawn can capture either rook or bishop and I capture the bishop, it says it is blunder, but it should be missed win.
But if the move is losing nothing, and cannot win anything, very bad move will it be a blunder or missed win? 

there is a point that the computer thinks that after a move a player is winning so much that he is basically winning effortlessly. For example after you capture a queen leaving your opponent with no counterplay the computer evaluates it as completely winning even though it can't spot a forced mate immediately. However a blunder means that after you had made a move that changes the winning bar a lot , but if after you had played the best move, your opponent would have some counterplay.

If you missed that you are checkmated in 1 move or giving away one of your pieces that is called a "blunder". If you missed that you could have checkmated your opponent's king in 1 move or captured one of your opponent's pieces that is also a "blunder". 

Missed win (?) = turns a won position into a drawn position
Blunder (??) = turns a won position into a lost position

My understanding is that missed win = u are already in advantage but u missed a move that helps u gain further advantage. U missed it but still have the advantage.

Blunder means u made a move that gives your opponent huge advantage (e.g. turn your position from winning to a drawn or lost position)

Not necessarily

chess hard i have 16 blunders in one game against giant help