PHP - Printing site_url and base_url in the ci framework has the same effect?

Question

Why do I use the site_url() function and the base_url function in my ci framework to have the same effect? The printed results are exactly the same.

Answer 1

Excerpted from CI documentation

This function is the same as the site_url() function, except that index_page or url_suffix is ​​not added after the URL.