HTML: markup language composed of tags that describe the content of a webpage. HTML therefore is said to “structure” otherwise unstructured text and image content
CSS: stylesheets that define the look and feel of your content
JavaScript: one of three core technologies of the world wide web enabling interactivity on a web page
jQuery: a JavaScript library that supports interaction in websites. Designed to make it easier to navigate a document, select DOM elements, create animations, handle events, and develop Ajax applications
Bootstrap: an open source responsive framework for building websites that work across display devices
D3: a JavaScript library for producing dynamic, interactive data visualizations in web browsers