Figure 1. Web apps are built in HTML, CSS, and JavaScript. It doesn’t matter whether your web app was written using React or some other library, such as Angular, Knockout, or jQuery.

Use this handy, simplified guide to quickly learn HTML and CSS -- a foundation of modern web development.

The Meaning Of HTML HTML stands for HyperText Markup Language. Understanding the basics of HTML is important to web development and almost anyone working with a website. HyperText HyperText is ...

CSS: Enter CSS to be applied to the HTML used in your tests. It is placed between <style> elements in the header portion of the page. HTML: This area allows you to enter HTML to be used in your tests.

How to Make a Web Site Part II: Styling and CSS Once you've got basic HTML down, it's time to learn styling and CSS so you can make your HTML look the way you want it. This lesson covers the basics.