How would you explain story points to a team who's new to Agile/Scrum?

Time vs effort.. teams get hung up on time based estimates. And not about the amount of effort it's going to take to accomplish a task/user story.

It’s about demonstrating it to them and comparing the efficacy compare to other frameworks via dissecting a story vertically to the smallest size possible.

I said I would talk to them about t-shirt sizing and try several ways to help them understand that story estimation has little to nothing to do with time, rather effort. I also explained that this was a challenging topic for a new team.