So I learnt about minority attack few months ago where you push pawns on minority side to create weaknesses on opponents pawn structure but recently I have also been seeing some masters casually telling to push on majority side to create passed pawns and that too in the middle game. So now I am confused as to which concept to apply and when. Any suggestions on this?
- Aim of minority (call it "_") attack: You already said it. This is almost by definition the only aim. If the enemy king is on that side, you might better call it a pawn roller, but of course the aims are not mutually exclusive.
- Aim of majority (call it "+") attack: Copy same sentences. :-)
So to answer your question, first ask where the two kings stand.
- Both kings stand on _. Hands off the _ pawns, it is too dangerous. Play on +, shoo the enemy figures around with your bigger pawn force, make a passer. This also distracts the opponent from making trouble on _.
- Your king on _, enemy on +. Ditto, and you get the bonus that the enemy king is feeling uncomfortable. Hurry, since the opponent does the same and has less barrieres to crash!
- Your king on +, enemy on _. Do a pawn roller on _, it ruins the opponents structure and exposes the king. Your opponent will try the same on +, but your king is safer.
- Both kings stand on +. This is the "standard" case. You can do a minority attack on _. If and only if the opponent can't crash through in the center, you can also do a pawn roller on +, gaining space and threatening the enemy king. (E.g. common in the Sicilian for White or Kings Indian for Black.)
Chess is very concrete and tactical, and these only were the basics. If I would now begin with the influence of figure positions, space advantage, or that it is long known how to defuse a "classic" minority attack by b5 and plugging a knight on c4, this answer would reach to Mars...
What constitutes correct Pawn play depends on what support they can get from their pieces. The classic example is the exchange variation of the Queens Gambit Declined. After 1. d4 d5 2,c4 e6 White at some stage plays cxd5, brings his major pieces to the Queens wing and pushes his Pawns on that side of the board. The resulting Pawn exchanges may leave a single Black Pawn on that wing, whose value as a passed Pawn is negated by the presence of Whites heavy pieces. It may well prove a weakness that can easily be picked off. White is able to do this because of moving first, but how can Black respond?
Tradition has Black reacting by building a King-side attack which will hopefully crash through while White is busy on the other side. Quite often this will involve advancing (some of) his majority, not to create a passed pawn but to drive away the White defenders. Black does this because there is usually no other plan available.
These decisions are made in the opening and early middle game. Later on, we may find ourselves entering an endgame with whatever Pawn structure we happen to have. The best plan may have little to do with majorities and minorities. It may be about the creation and exploitation of weaknesses by other means. But it is quite likely to involve creating and exploiting passed pawns, often by pushing your majority, wherever it happens to be. However, you should always bear in mind the possibility of those Pawns being "overextended" (Far from home, cut off and vulnerable) Passed Pawns are only dangerous if they have support and can avoid being blockaded. A decisive factor is often the availability of the King for both attack and defence.