Why is it called real estate?

From WhyNotWiki

What's with the word "real"? We don't call "cars" "real cars".

Why not just call it "estate" or something?

[edit] Answer

Thanks to Ethan for setting me straight and pointing me to Wikipedia...

"It's 'real estate' because it is 'real' property, as opposed to 'personal' property"

So there is a real estate and a personal estate ... together they make up everything a person owns, their estate

Real property is basically land and improvements on that land.

Real is for immovable property, personal is for movable.