The Ascendant:Ascendant (Udaya lagna in Sanskrit) is the degree of zodiac intersected by the eastern part of horizon at the place and time of native's birth. Udaya lagna represents Earth as a planet in a chart.
Midheaven, - the point of zodiac directly overhead. It is the cusp of the tenth house in Vedic Astrology.
Midheaven house system:
It is system where difference between Ascendant and Midheaven divided equally. This method is used in Sripati system and works well in areas in close proximity to equator. For areas, which are further to north (like Europe) other house system can be considered as more suitable.
Equal house system:
This system regard Ascendant as a cusp of first house and place all other house cusps an equal 30 degrees from it. The disadvantage of equal house system that it doesn't consider Midheaven adequately. This system more suitable for extreme latitudes.
Cusp is the most important and powerful point of house. Planets located at the cusp have the strongest effect and most typical meaning of the house.
Cusps - difference in Vedic and Western Astrology:
While Western astrology considers beginning of the house as a cusp, in Jyotish cusp marks the middle of the house.
Houses are considered from the Moon in Vedic Astrology:
Chandra lagna is used mainly in equal sign system. Moon as ascendant helps to verify state of different houses. There are 2 different approaches for cross verification of bhava. First uses Udaya lagna, Chandra lagna and Surya lagna. Second system uses Udaya lagna, Chandra lagna and verification in (D-9) Navamsha. Also, reading from Moon at rashi chart can give information about astral body of client. In cases when exact birth time is not known, reading can be done from Chandra lagna.