New in the domain ARDUINO

Hello everyone, I am faceted by the arduino card, I would like to know if I make a upload in my arduino uno card and I want to change a new project, I make the direct upload or you have to reset the card ???
if not how??

MERCI.

Whenever you upload a sketch to the Arduino it overwrites what was there (mostly). No need to reset anything.

Thank you for the information. It reassured me a lot on that point.