You busted me: I guess that's my age showing because I didn't know Excel -had- a new data model. What's it called and how is it different than sheets, and when

You busted me: I guess that's my age showing because I didn't know Excel -had- a new data model. What's it called and how is it different than sheets, and when was it introduced? I was using Excel2013 up until I left the project in 2014.