Load & Include
There is a small difference between "load and include" methods:
Loads target file only once, regardless that file is called many times with the load method.
Includes target file as many times as it has been called with the include method.
The main object is that, these methods execute codes at the line where those two methods are called. Hence, please be careful about loaded and included files are executed at the same scope of the function of where the load or include functions are executed; this might affect the declaration of variables.
Check the example below:
Adding Local Files to Project