I finished developing my PHP/MySql website, Do I need a configuration file?

I have finished my first PHP/MySql website and all what left now is me uploading it to a server. but I'm not quiet sure that this is all

I've read about config file many times but I don't know if that was for php or ASP.net.

Can you please guid me whether I need one or not, and if so, what is it called?