what is the difference between site_url() and base_url()?

Question

As I have read in some resources, base_url() and site_url() functions in codeigniter are almost the same, although my version of code

Answer 1

site_url: Returns base_url + index_page + uri_string

base_url: Returns base_url + uri_string

See source code of both functions at: https://github.com/EllisLab/CodeIgniter/blob/606fee0e2e0aa6a906db82e77090e91f133d7378/system/core/Config.php