Wing Chun is not just a collection of unrelated techniques. It has a core set of guiding principles which allows practitioners to decide what is correct or incorrect Wing Chun. This keeps the art a pure and integrated fighting system, while allowing direction for refinement that is consistent with its principles.
These guiding principles are strictly practical and is part of the reason for Wing Chun's uniquely scientific and logical approach to fighting. It is likely that Bruce Lee managed to develop Jeet Kune Do from Wing Chun because Wing Chun trained him to think about fighting in a scientific way.
All Wing Chun techniques have a practical purpose. There are no flowery moves or graceful techniques that mimic animal movements. To the uninitiated, Wing Chun can appear less effective when compared with more dramatic styles. Like Hsing Yi, another linear style, Wing Chun practitioners pride themselves on plain-looking but effective techniques. The crowd-pleasing elaborate moves used by Bruce Lee in his movies are not real Wing Chun or Jeet Kune Do. Bruce Lee consciously choreographed more flamboyant moves to entertain his fans. His actual fighting style was simple, direct and effective.
Following this utilitarian approach, the names of Wing Chun techniques are purely descriptive. For example - bounce hand (tan sau), wing arm (bong sau), slapping hand (pak sau). Wing Chun terminology is traditionally rendered in the Cantonese dialect of Chinese.