Complete solution vs General solution of a PDE

Question

I am unable to understand why the general solution is a "bigger set of solutions" than the complete solution.

What is the intuition behind this?

Source of the quotation:

Answer 1

The general solution involves arbitrary function of known function's $u$ and $v$, while the complete solution involves arbitrary constants. The arbitrary function is more general than arbitrary constants as it include all possible functions of variable and constants, so I think that's the reason.