Each house represents a cluster of interests and activities just as each sign represents a cluster of traits and approaches for dealing with those activities.
The spheres of interest of each house are as follows:
First - Self, appearance.
Second - Earnings, possessions.
Third - Communications, relatives.
Fourth - Home, parents.
Fifth -Pleasures, children.
Sixth -Health, service.
Seventh - Spouse, partnerships.
Eighth - Death, regeneration.
Ninth - Philosophy, travel.
Tenth - Career, status.
Eleventh - Friends, aspirations.
Twelfth - Secrets, limitations.
The intensity of a planet’s influence on a house depends on the sign of the zodiac that happens to fall on that house in your zodiac. If Cardinal Signs are found in Angular (Cardinal) Houses, they strengthen the planetary energies flowing into the activities of the houses, etc.