The Ascendant in a birth chart is known as the rising sign. It is the starting point of the first house in a chart. Contrary to the standard horoscope analysis in the newspaper, where the personality of a person is based on the Sun Sign (the sign where the sun is), astrologers usually put emphasis on the characteristics of the first House, or Ascendant, to project a personality profile.
On the birth chart, the Midheaven is the point where the sun is found midday. The sign where the Midheaven is found not only has a strong bearing on the subject's outward expression of oneself in one's world, lifestyle, choice of career, attitude, but also in events that the subject has no direct control. The Midheaven represents ego, and the characteristics that are associated with the sign in which the Midheaven is found, are expressed in an external manner.