Microcontrollers do have internal pull up-pull down resistors yet most of the circuits have external pulling resistors.
I looked on Google for answers and a few sites said that those resistors are not that strong but I thought they were good enough to work. I had the thought that they might need external because the internal resistors need to be triggered by programming.
So for some unplanned situation, they attach external resistors as well. But I'm not certain about it.
What is the real reason behind using externals when we do have internals?