These situations can easily occur if the pawn structure is weak.
Now, the whole strategy of a game may be based on pawn structure.
It may lead to good endgames for Black, who has the better pawn structure.
Bg2 h5 will force a weakening of White's pawn structure, and 2.
And sometimes, of course, the best way to have piece activity is to smash up the pawn structure.
The more symmetrical the pawn structure, the better it is for the knight.
It emphasizes piece play while keeping the pawn structure flexible.
See the diagram for the pawn structure most typical of the French.
Despite the symmetrical pawn structure, White cannot force a draw.
Complex criteria such as king safety or certain pawn structures.