What is first GPO or Regedit?

Hi,

I would like to know what GPO policies or Registry entries are primarily for.
Ie. If in the registry the I turn off screen saver and in the local or domain GPO is on, will the GPO overwrite the entry in the Register or will it have a shortage? Of course, I have administrator rights on my computer and also for DC. I know that when it comes to GPO, LSD OU is in effect. But what does GPO vs Registry look like which is first? Or am I missing something?