Ascendent

The Ascendant is the degree of the ecliptic which is rising over the Eastern horizon at the precise time and place of an individual's birth. Put more simply, the Ascendant Sign is the sign of the zodiac which is rising in the East at the moment of birth, and this sign, and the exact position of the Ascending degree, are the starting points in any astrological interpretation.
The Ascendant shows us as we really are - as opposed to the Sun sign which represents our ego and how we would like to be. This is most strikingly obvious if one talks about a person to someone who a casual acquaintance, and describes their character as shown by the Ascendant Sign - in the vast majority of cases, the third person cannot identify those traits as belonging to the subject at all, because Ascendant Sign traits are those that emerge only to those closest to us, and who know us really well.

Aspects

CONJUNCTION 0 Strong focal point. Energies of the two planets are fused but not modified.

OPPOSITION 180 Tension and conflict. The energies of the two planets are at loggerheads.

SQUARE 90 Difficulty and discord. The energies are fighting to become dominant.

TRINE 120 Strongly helpful. The energies flow freely and complement one another.

SEXTILE 60 Generally helpful, but occasionally both energies are wasted.

QUINCUNX 150 Stressful. The two energies strain each other, neither working to best effect.

SEMI-SEXTILE 30 Slightly stressful, although one energy may be dominant and work well.

SEMI-SQUARE 45 Difficult, but less so than the square.

SESQUIQUADRATE 135 Irritating and annoying rather than difficult. Energies are unpredictable.