HTML stands for HyperText Markup Language. It is the standard markup language used to create web pages and is an essential part of web development. HTML allows you to structure the content on a web page by using various elements and tags, which are used to define headings, paragraphs, links, images, forms, and more.

HTML documents are text files that contain HTML tags. These tags are used to describe the structure of a web page and provide instructions to web browsers on how to display the content. HTML tags are enclosed in angle brackets, and they come in pairs, with an opening tag and a closing tag. The closing tag usually has a forward slash before the tag name.

HTML is the foundation of web development, and it works in conjunction with other web technologies like CSS (Cascading Style Sheets) for styling and JavaScript for adding interactivity to web pages.