Since the HTML/CSS mixture is comparable to the data located in a Word file, it is good only for exhibiting information.
If you want your web pages to do different things based on the scenario, you’ll want a programming language. For example, some sites want to supply a membership facility where individuals can log into the website, and get certain advice. Other websites provide a feedback form so that visitors can contact them. All these matters require facilities a straightforward document format cannot do.
Aside from the preceding difference, from the standpoint of a non-programmer, there is not much point asking what the difference is between the languages, say, between PHP and Perl. It would be like asking what the difference is between English and German, or some other human language. They are merely different languages you can use to write internet-based programs. Each computer language has its own strengths and weaknesses.
Learning a programming language is enormously different from creating a site whether with a web editor or directly in HTML. Although I’ve tutorials for things like learning to write programs in PHP (and the other languages), many people would find programming a difficult endeavor, unless they already have a programming background or an inclination towards programming.