Front-end Developer Handbook 2017

Don't learn jQuery, learn the DOM. Don't learn SASS, learn CSS. Don't learn HAML, learn HTML. Don't learn CoffeeScript, learn JavaScript. Don't learn Handlebars, learn JavaScript ES6 templates. Don't just use Bootstrap, learn UI patterns.

Cascading Style Sheets (CSS) is a style sheet language used for describing the look and formatting of a document

JavaScript is prototype-based with first-class functions, making it a multi-paradigm language, supporting object-oriented, imperative, and functional programming styles.