The definition has changed significantly over centuries:
Roman Empire: Originally, the villa was a Roman estate. A distinction was made between the villa urbana (a purely luxurious country residence for relaxation) and the villa rustica (an agricultural operation). [1, 2, 3]
Renaissance: In 15th and 16th century Italy, the term revived. Wealthy families built magnificent, representative country houses (like the famous buildings by Andrea Palladio). [1]
19th Century (Founding Era): With the rise of the bourgeoisie, the villa moved into the city. So-called villa districts emerged on the outskirts of the city. [1]