# Why should I use a pull up/down resistor for a GPIO output pin?

I know there are lots of similar questions and read them, but I need a simpler and clearer answer.

I understand why and how to use a pull up/down resistor when using a button (GPIO input). But while configuring a GPIO pin which will be connected to an LED, what is the use of these settings?

I tried no pull-up and pull-down and pull-up for example, but I could not see a difference in the implementation.

I am using STM32F407-DISC.