The following three words are commonly used in interior design and related books. Sometimes still it’s not obvious when to use which.
Antique: marker of furniture, objects of art, or artisanship older than 100 years, independently of style. Its age, originality, condition, the manufacturer and rarity is important for collectors (full collection in case of a set). A restoration gives them back their original pomp.
Vintage: marker of objects that are younger than 100 but older than 15 years, concerning rather to their condition than age. It is a classification of strongly used, shabby surfaced furniture and household objects which marks even a style. It means rethought, reused, modified/renewed objects also. Giving vintage look to a new object is a distinct genre. It is not equivalent with the shabby chic style.
Retro: marker of household and decoration objects of years from the 50s to (presently) the 80s. Their age is old „only”. It is also a marker of objects that are new but made look like in the style or shapes of this era. Collectors are motivated by nostalgia and emotional bondage but of course originality and condition are also important. Retro has a pejorative meaning, “out of fashion”.
In case of uncertainty, ask for help of a professional dating an object.