Making video games run better is like making sure a car runs smoothly. Game developers work on improving how fast the game loads, how well it performs, and how stable it is, so players have a great time playing no matter what device they use.
This means tweaking different parts of the game, like the graphics and the code, to make sure everything works perfectly. By doing this, developers make sure players get to enjoy awesome graphics and fun gameplay without any annoying glitches or slowdowns.