agile

So I have this confusion about the roles of Release Manager and Delivery Manager. I thought they were the same thing but apparently I'm incorrect in believing that.

From what I could piece together, both roles are about releasing stuff and taking care of operational aspects of that release (like bugs coming back in, performance issues that need to be fixed, etc).

Delivery Manager seems to be another name for Project Manager, while Release Manager seems to be another name for Scrum Master. I understand the first statement somehow, but the second statement doesn't seem to make sense since, from what I know about Scrum, the Scrum Master isn't concerned with releases but with the Scrum enactment.

If someone can shed some light into the situation, my questions would be:

Are a Release Manager and a Delivery Manager the same thing or not? What are the differences and similarities?

Is a Release Manager a function in classic project management and a Release Manager a function in Agile?

I understand that roles don't mean much as each company override them or redefine them to mean various stuff, but is there a core definition for these roles? What do Release Managers and Delivery Managers do?