Fundamental Languages

Question

What are the fundamental languages that every web developer must know?

Answer 1

HTML, CSS, JAVASCRIPT, PHP, SQL

Answer 2

Fundamental? HTML5, CSS3, and Javascript.

However, I would expand beyond that so you can create something that meets up with modern expectations of websites. For example, maybe learn PHP, NodeJS, MySQL, jQurey, Angular, React, etc..... All of these things adds further functionality to what you're doing so you can provide your visitors with a full experience instead of a rushed one that doesn't have what they expect a site to have today in 2017.