If you go to an “estate sale”, you’ll generally find that everything not nailed down is being sold.

What will remain, that can’t be carted off or removed, is the “real” estate. The land itself, the permanent structures.

It’s why a house sale includes a bunch of information about things like appliances, mineral rights, the things that are being included that arent “real” components of the property, because they could conceivably be removed prior to closing, because purchasing “real estate” doesn’t automatically include those things inherently, and you want all the estate that isn’t “real property” to be codified.

Estate sale vs “real estate” sale, is the basic difference.