>>52640855>>52640855https://bulbapedia.bulbagarden.net/wiki/Action_speedThe Bulbapedia article on action speed is decent, but I can boil it down
Everyone gets a starting "action time" based on their speed stat
The action times count down and the Pokemon gets a turn when it hits zero (it calculates everything in advance which is how it shows the turn order preview)
Strong style adds to your action time so it takes longer to hit zero
Agile style can either add to the target's action time or lower your own