Yep, PHP is obviously server-side scripting that doesnt do any client-side stuffs. So, you should rely on Javascript to do client-related functions, for example:
- Do you notice the smiley icon? when you clicked em, they will add themselves to the textarea. 🙂
- Open a new window
- Quickly check your input and warn you before your data is submitted to the server
and countless others, you name them.
Javascript can take benefit from PHP in the way that you can echo or print the value of, let say, daily news stored in MySQL database to the scrolling news javascript. This is just an example.
I wouldnt say that it is 'multiple languages' at the same time. In fact, a php website will consists of (at least for me) HTML/XHTML, Javascript, CSS, PHP, and a database. So, you'd better know em enough to build a dynamic website. 😉