HTML, or Hypertext Markup Language, is the standard language used to create and structure web pages, comprising elements that inform the browser on how to display content. A web page includes essential parts such as <html>, <head>, <title>, and <body>, containing various elements like headings, paragraphs, and images. HTML elements use tags to signify content structure, and certain tags, such as <div>, <br>, <b>, and <i>, serve specific purposes in formatting and organizing the webpage.