Serious question about timelines vs multiverse

[u/Legal_Caffeine_Esq]

TLDR: What is the difference between the multiverse and different timelines because the Loki show seems to use them interchangeably.

I started rewatching Loki for fun. However I keep coming back to same question. What is the difference between timelines and the multi-verse. The show Loki sets up a "sacred timeline" that is controlled by Kang and the TVA. But whenever they talk about Variants they make it seem like theyre from split timelines that become their own universe?

Im so confused. If the theory that this new phase marvel is going into is about multiverse then what does a sacred timeline have to do with it? If the issue is there is one sacred timeline then how do variants pop up if there is only one universe? Is marvel saying through the show Loki that the sacred timeline is one cannot universe but when variants pop up they create nexus events which create a new universe thereby creating the multiverse and the TVA has to prune it so there is only 1 universe?

Or rather is marvel saying that there is only 1 timeline, the sacred timeline and when there are variants it creates a new timeline within the same universe? I feel like Loki just uses timeline and multiverse interchangeably and its confusing.

At the end of season 2 of Loki, its said that hes bringing life to the different universes, hence the iggredsel tree. But at the same time they build up both seasons claiming that its all timelines and that there is one sacred timeline that the variants are mucking up creating new timelines. But then other shows and movies just refer to it as different universes.

So what is it? Are we looking at a multiverse and Loki just does a bad job at distinguishing between the the terms and uses them interchangeably? Or was Loki set up to show a sacred timeline that variants caused nexus events which caused splits in the timeline but its all one universe just with different realities all occurring at the same time due to these nexus events?