HTML documents contain the text to be displayed and markup tags which tell the Web browser how to display the text. Markup tags define the structure and style of the document and how one document is connected to another through hyperlinks .
Tags usually come in pairs.
The beginning tag tells the Web browser to start formatting in a particular style and the ending tag tells the browser that formatting is complete. Because it is used to search Internet documents, every document should have a title. The title should be short, yet informative. The title is usually displayed separately from the rest of the document. Headings HTML has six levels of headings numbered 1 through 6, with 1 being the largest.