You have to train your mind to recognize a chess pattern on the board during a game. To become a strong player it is necessary to know all sorts of patterns to be able to use them when a given position in your game arises.
A pattern can be a tactical theme or plans that are available in given pawn structures. The more patterns you know, the stronger you become, as this will make it easier for you to handle many positions in your games.
Patterns have names such as:
more space in the center
open lines
weak squares
pawn majority, pawn minority
two weak points to attack - the Principle of Two Weaknesses
weak kingside
weak queenside pawn structures
inactive knight at the corner
dead bishop
weak isolated d-pawn
insufficient piece coordination
attacking mark
free protected pawn
bishop pair
better minor piece in open position - bishop versus knight
better minor piece in blocked position - knight versus bishop