What are the diffraction between include and require? Which is good to use?

Answer 1

required will give an error if the file is not found. it is good to use if the file contains core functions. there is also required_once and include_once for no duplication of imports. hope it helps ^.^

Answer 2

If the file is not very important to run your php script, you should use include and if the file is very important ( like file that has functions for validation) in order to run your php script you should use require_once() .