Php , ajax & jquery

Will these languages have any need demand in the current market .
Advice for a buding developer ?

The first one is a language, and yes, it’s a popular language.

The second one is not a language, it’s a technique (using JavaScript), for getting data into a web page without reloading the page. It’s used extensively, but it isn’t a language or a library, it’s a technique. It doesn’t make sense to ask if there’s any demand for it, it is just a necessary thing that is done.

jQuery isn’t a language, it’s a JavaScript library. There is less need for it now than there was 10 years ago: it used to be added to new projects as a default, but that is not the case anymore. It isn’t necessary to know it, but if you know JavaScript it is trivial to learn to use jQuery.