## Hypertext Markup Language (HTML)

HTML is the Web’s core language for creating content for everyone to use anywhere. The World Wide Web's markup language has always been HTML.

HTML was originally designed as a language for semantically describing scientific documents, but its general design and adaptations over the years have enabled it to be used to describe a number of other types of documents.

## Cascading Style Sheets (CSS)

Style sheets describe how documents are presented on screens, in print, or perhaps how they are pronounced. Cascading Style Sheets (CSS) is a style sheet mechanism that has been specifically developed to meet the needs of Web designers and users.

## JavaScript

JavaScript is a cross-platform, object-oriented scripting language. It is a small and lightweight language. Inside a host environment (for example, a web browser), JavaScript can be connected to the objects of its environment to provide programmatic control over them.

Client-side JavaScript extends the core language by supplying objects to control a browser and its Document Object Model (DOM). For example, client-side extensions allow an application to place elements on an HTML form and respond to user events such as mouse clicks, form input, and page navigation.