There are a lot of terms currently being used in wing chun to define some sort of mythical force it is able to generate. One of the oldest terms is gung lik, the newest is force flow and there are others such as fa jing, chi and nim lik (Chu Shong Tin's term). In order to be polite I will label the majority of these as marketing. You are either using pushing and pulling (muscular contraction) or you are using what we at Sung call relaxed power.
Relaxed power feels different. It is smothering and multidirectional; annoying uncomfortable. You can only cultivate it to a useful level if you practice it purposefully. Some may get it by chance after many years of training, but most others just get more tense and eventually injuries lead them to giving up. A lot of people do think they have it, they show how loose their muscles are in their arms when at rest, but in order to create any force they lock their shoulders and tense up at the last moment of the hit. Sorry, but it you tense up on contact (even when you punch) then that is not relaxed; you are kidding yourself. If you do not believe me when I say you should not tense on contact, then there is a whole new world of relaxation you can work on.
This is not a dig at using muscular force, it is a tremendously powerful method and the basis of most arts. I won't say relaxed power is better, just a better fit for those who do not have much mass and want to avoid injury (time lost on injuries is a major reason people give up training). It is body mass which is the key, as relaxed power is about making your opponent deal with that mass on first contact. Learn how to use that initially at a slow pace, then add acceleration to make it applicable in a fight.
I would estimate that only about 10% of wing chun practitioners have any idea about relaxed power. You will not find the secret on youtube, FB or down the back of the sofa. You have to feel it to get a grasp of it. Another problem can lead from it in that those who do have it go one step further and start claiming they have internal powers, but again it is probably only 10% of those who have that either. What is internal power? Now that is a good question I will leave those who are best qualified...
Note - the term Relaxed Power (c) is now copyrighted and trade marked to Sung Wing Chun. Anyone who dares to use it from now on risks me blocking them on Facebook and all social media until they say they are sorry.
Keeping you up to date with what is happening in class