The 10th house is the karma sthana — the work you are structured to do. Its sign shows your working style; its lord’s placement shows where career fortune flows; planets sitting there colour the profession. Sun there leans authority and government; Mercury commerce and communication; Saturn slow, durable mastery.
The D-10 divisional chart then magnifies this house into a full career map. Together with dasha timing, they answer direction, environment and phase. Career astrology in full.