This term gets thrown around a lot by architects, designers and contractors but many people don't know what it really means. This video explains the differences between the levels of drywall finishing.
Here is an in depth document if you want even more info on the subject.
https://www.usg.com/content/dam/USG_Marketing_Communications/canada/product_promotional_materials/finished_assets/cgc-construction-handbook-ch05-finishing-drywall-systems-can-en.pdf