Is php a requirement for back end web development?

Question

I’m currectly picking up HTML and css and will eventually go on to js, from what I’ve briefly read, I might just be able to use node.js.

I’m just unsure of what exactly php is used for and whether I can just use js in its place.
Any help would be appreciated.
Thanks

Answer 1

You can’t really compare JS with PHP, because HTML, CSS and JS are client-side languages and PHP is a server-side language. For PHP you need an own or accessible webserver, whereas HTML, CSS and JS just need a local client (browser).

Answer 2

No longer a requirement but can help.

Answer 3

Most of current web servers platforms packages like XAMPP and LAMP are using php so it's will help if u learn it