At its most basic, the Alexander Technique is a method for addressing and changing our most deeply ingrained harmful habits.
By a process of resisting, or inhibiting a familiar reaction to a stimulus, and then of replacing the habitual response with a series of reasoned directions, the teacher is able to help the student become aware of what they are doing wrong, and move towards a healthier use of their body in every day life.
Inappropriate Sensory Awareness makes control of physical habits based purely on one's own bodily sensation difficult. If any bodily sensation is present for long enough, we cease to feel it, leading in some cases to inaccurate awareness of what we are actually doing. Anyone who has watched himself in the mirror while trying to imitate the motion of another person will be aware of this issue.
Means Whereby is the method by which one chooses to reach a goal.
End-gaining refers the habit of entering into an activity in a habitual way, without taking time to consider the means whereby.
Primary Control refers to an optimal relationship of the head to the neck, and of the neck to the torso which is indicative of healthy body use at large.
Conscious Control is the goal of Alexander Technique - that is: a complete awareness of what the body is doing, and the ability to control the response accurately.
Non-doing is beautiful movement in an Alexandrian sense. It is characterized by lack of effort, ease, flexibility, and inhibition of habitual response.