Reset Button

Please forgive me if this is a dumb question! I’m old, very old trying to keep brain and body in sync with Arduino.
Question: does the reset button delete the last ‘Sketch’ before uploading another or does uploading a ‘Sketch’ automatically over-right the previous one.
Thank you for your understanding

Reset merely restarts the Arduino. Thus, going through setup and resetting global variables. It does not erase your installed sketch

And to add, uploading a new sketch deletes the previously loaded sketch.

Dear,

If you press a reset buttoonm, the sketch restarts.
If you upload a new code, it overwrites the previous code.

Thank you,