[1] It is a special type of zugzwang and most often occurs in endgames with only kings and pawns.
Taking the opposition is a means to an end, normally to force the opponent's king to move to a weaker position, and is not always the best thing to do.
Direct opposition is a position in which the kings are on the same rank or file and are separated by one square.
If it is Black's turn to move, White has the opposition and wins.
If it were White's turn to move, Black would have the opposition and the position would be a draw.
In order to ensure correct play in situations like in the diagram, it may be helpful to remember that each time the pawn steps forward, it must be without giving check.
If the pawn checks the opponent's king, the opposition will be lost and the game drawn.
In the game Svetozar Gligorić–Bobby Fischer, 1959,[4] Black can draw by keeping the white king from getting to any of the key squares (marked by dots).
[7] Distant opposition is a position in which the kings are on the same rank or file but are separated by more than one square.
If there are an odd number of squares between the kings, the player not having the move has the (distant) opposition.
White must remember that the aim of the opposition is to penetrate, so to step sideways and forward with ...
Since the black king has been forced to step aside to the h-file, White can now penetrate on the f-file.