Here is some explanation of the terms and method that I use to delineate charts. You want to know what astrology is? It is about studying the interaction between symbols in the sky (as seen in the eyes of an astrologer) and real life events.
METHOD
Some decades ago I started to study astrology. First I learned the method used by Dutch astrologer Ram. Then I read a lot and did some research on my own, for example about astrology and the length of life, and comparing generals, politicians and bikers. When I discovered COSI, the famous book of Reinhold Ebertin, midpoints, aspect combinations and the value of narrow orbs were introduced. Noel Tyl's Vocations inspired me so much that I decided to go to Lisbon for the workshop there:). This all and many own studies, books and internet sites brought me to the present eclectic method that I use. For this, and how to read a chart, see:
http://astropost.blogspot.nl/2012/11/three-steps-to-analyze-natal-charts.html
VOCABULARY
Major aspect: conjunction, sextile, square, trine and opposition. Those are the Ptolemaic aspects.
Minor aspect: semi sextiel, semi square, half semi square, semi sesqui square (67.5), sesqui square, septile, (bi)quintile, novile (40d), binovile and inconjuncton (quincunx) or quindecile (165 d)
Minor aspects are not related to signs and their harmony/disharmony. Minor aspects are often of major importance.
Calling: without major aspects in sign or orb 5 degrees.
Crucial: placed on the corners of the cross of the chart (angular, or square the Ascendant)
Midpoint: point in between two planets
I use not to mention the nature of the aspect in a midpoint combination. For example: Sun/Mercury sesquisquare Mars is Sun/Mercury/Mars or Mars on Sun/Mercury for me. I see the three as one aspect combination.
Midpoint combination: a combination of a midpoint and another planet in hard aspect (0,45, 90, 135, 180 degrees) away from the combination with a maximum orb of 2 degrees)
Midpoint Yod: a planet is opposite the midpoint. Example Sun/Moon opposition Neptune. In this case Neptune is a very important focal point of motivation
Orbs: I use very tight orbs, 5 degrees max and when not in sign, I even like them tighter:). Exception: "translation of light"...
Orientational/oriental
The outer planets are Mars, Jupiter, Saturn, Uranus, Neptune and Pluto.
I name the first outer planet that is rising before the Sun: planet of orientation. It is the symbol of what is first of all important for you.
Mercury and Venus are not planets of orientation, unless Mercury or Venus are 'calling' or at an angle, that is: prominent.
Translation of light: an aspect made with two planets who are out of orb, connecting both planets (in which case I use this aspect, even if out of orb or out of sign
OOB or Out of Bounds, see http://astropost.blogspot.nl/2014/01/out-of-bounds.html