Madden 20 Defense?

I'm currently playing Madden 20 on PS4. I also have no problems or anything, the only thing I don't understand is when to press square, when to play defense, and when to press X. Can anyone explain this to me? ^^

Well we say you play a linebacker or cornerback in defense, if the ball is flying towards you you can press square to swat the ball i.e. Try to hit the ball with all your strength so that the opponent doesn't get in but you can also press the triangle to try to intercept the ball. Catching the ball as a defense player.

If you say we play linebacker or any other position you press X to do a precise tackle without full speed