It is a little of both. Horoscopes in the newspaper make a statement about a whole sign group, so the “predictions” are generalizations. The writer checks the current alignment of stars and planets based on what houses they are in, and then uses the general “meanings” of different alignments to make a statement. An example is “when Mercury is retrograde in Gemini : Because Gemini
rules communications, be prepared for miscommunications
when Mercury is in this sign. Expect lots of phone calls or none, and lost or misplaced mail. You may not articulate clearly, and gossip abounds. Old friends may reconnect.” Some writers just make shit up with as much relevance as a fortune cookie.