How can I save a PHP file with a .php or .html extension?

Question

Why do we have a PHP file as .php? Can we save a PHP file as .html, because at some sites, I have seen webpages with the .php extension? Why can\'t we have a .html extension

Answer 1

An alternative to kjy's answer is to use URL rewriting, it will let you use whatever page extensions/file names you want.