The first house, of which the cusp is often (but not always) the Ascendant. The first house signifies the person in the chart, his or her personality, and his or her behaviour. Quite often the Ascendant can overshadow a person's Sun sign. For example, a person who has Leo on the cusp of his or her first house and Virgo as his or her Sun sign can be quite dynamic and dramatic, but the fastidious, efficient, self-effacing part of him- or herself will not be readily apparent until people are able to pierce through the persona and see the real person.
The fourth house, of which the cusp is often (but not always) the Imum Coeli. It signifies a person's home, security, family, and those things in early life that served as a foundation for them. The fourth house is sometimes also connected with endings, such as a person's end of life. This house is often affiliated with our parents. For the ancients, it was the House of the Father, but in modern charts, it tends to have a more general parental significance.
The seventh house, of which the cusp is often (but not always) the Descendant, shows the type of mate the native is likely to be attracted to and all partnerships in general. For Hellenistic astrologers, this house had a somewhat sinister significance to it, for factors heavily weighted here indicated enemies and adversity.
The tenth house, of which is often (but not always) the cusp is also the Midheaven, refers to our careers, vocations, creative output, and how we would like the world to see us. For Ptolemy, it also was the house where our children's impact can be seen.
The cardinal, or angular, houses of the horoscope are considered to be the most ardent, or forceful, and are considered to have the greatest impact in the chart because of the aggressive nature of the houses. To summarise, the cardinal houses rule those critical things in our life, such as our appearance and how we behave, our family life, our married life or partnerships, and our career.