jeez louise i can't respond to every stupid post, but it's not like astrology. or if it is like astrology, it is only in the broad way that people both think they're "dumb."

astrology you receive a spiel that is more or less random, irrespective of anything except your birthday. useless.

personality tests or w/e take an inventory of questions about your personality, and then, based on your answers, give a composite picture of the kind of person who often responds in kind. this "profile" is nearly, but not exactly, tautological, and whether there is a lot of value-added probably varies pretty subjectively; if it provides you with the language/vocabulary/concepts to have a better understanding of yourself/your goals/drives/fears/dynamics in relationships, then such tests certainly have their pragmatic use. i'd say this value is often more than zero, but always less than whatever HR departments and grifters want to divine from it. but the tests are categorically not like astrology.