No. It's not really clear what LLMs do, but it certainly depends on context.

What they fundamentally do is continue a text. That's what they were originally trained to do. Then they were fine-tuned to continue a chat log or respond to an instruction. To be able to do that, they have learned a lot. Unfortunately, we do not know what.

If you ask for a summary of some text, it will give you one; regardless of whether the text even exists.

The summary could be one written by a human that it has memorized. Or it could be complete nonsense, that it is making up on the fly. You never know.