HTML, short for Hypertext Markup Language, is a standard markup language used to create the structure and content of web pages. It provides a set of tags or elements that define the different components of a webpage, such as headings, paragraphs, links, images, tables, and forms.

HTML documents consist of a series of nested tags, forming a hierarchical structure. These tags define the purpose and meaning of the content they enclose. For example, the h1 tag indicates a top-level heading, while the p tag represents a paragraph.