I've tried changing the settings, but it's confusing. Am I trying to stop my laptop from "locking", "sleeping" or "hibernating"? It's not clear to me which thin

I've tried changing the settings, but it's confusing. Am I trying to stop my laptop from "locking", "sleeping" or "hibernating"? It's not clear to me which thing it's doing. Maybe it's doing one thing some of the time, and the other thing the rest of the time. And even now that I think I've set it to do none of these things, the screen still disappears and I have to re-enter my password within 5 minutes. So either the settings don't work, or the UI is too confusing for me to figure out what's the right thing to do. Either way, putting a YouTube video on is much easier.