What is Gong(功)? Why it's almost ended at the end of most methods？

[ChiDragon]

Why is almost every method ended up with 功 at the end. Anyone would like comment on that?

Edited October 30 by ChiDragon

[Cobie]

 

工 gong1 - work

+

力 li4 - physical strength 

=

功 gong1 - achievement 

 

 

[ChiDragon]

44 minutes ago, Cobie said:

 

工 gong1 - work

+

力 li4 - physical strength 

=

功 gong1 - achievement 

 

 

That is correct.
To be more precise, in martial arts, it is something that was to be acquired, biologically or physically, from a method that requires diligent practice. 

[ChiDragon]

So, we have many 功(gongs). such as
1. Qigong(氣功), beathing method
2. Neigong (內功), internal method
3. Weigong (外功), external method
4. Songgong (松功) relaxing method