cool it's a very non-standard title, but here is what the google said and it's somewhat typical in my experience. in software - requirements are more agile "user stories" working with engineering.
Product Manager Job Responsibilities: Develops products by identifying potential products; conducting market research; generating product requirements; determining specifications, production timetables, pricing, and time-integrated plans for product introduction; developing marketing strategies.
so we're somewhat jack-of-all-trades-master-of-none in a specialist world. Working with marketing, sales, engineering in a sort of in-between role. Based on brand management from consumer world, but not at all the same.