12 houses
← Zodiac realms · Glossary: 12 houses · Zodiac
Twelve divisions of the local sky, fixed to the horizon rather than to the stars. Not the same twelve as the signs.
Houses are not signs
This is the distinction most often collapsed. Signs divide the ecliptic and are the same for everyone alive at a given moment. Houses divide the sky as seen from one place at one time, anchored to the eastern horizon, and so differ between two people born the same minute in different cities. The zodiac turns through the houses once a day.
In this app’s cosmology the houses sit with the Eighth Heaven, Muzaloth, as part of the moving machinery of cosmic timing rather than with the fixed stars of the Ninth.
That there are competing systems is the honest part
Placidus, Koch, Regiomontanus, Campanus, Porphyry, whole-sign — these divide the same sky differently and put the same planet in different houses. Whole-sign is the oldest attested method and is what Hellenistic astrologers actually used. No system is standard, which is worth stating plainly on any page that prints the number twelve as though it were settled.