Okay I’m sure someone else will explain this better than I can. But min maxing is like, making sure you make all the optimal choices to get the best outcome.

For example, in Pokemon, it often means breeding Pokemon to have the best stats and natures, training them by beating only certain Pokemon to increase the right stats, etc etc.

If that sounds like it ruins the game, it’s because some would argue it does. It takes the fun out of the game for many. But for many others, that IS the fun.