HTML tag encloses the entire HTML document. HTML tag divides the web page into two separate sections i.e. head section and body section.
Head section is defined by <head> tag, it represents the document's header, which can keep other HTML tags like <title>, <link> etc.
Title tag: The <title> tag is use to mention the document's title.
Link tag: The <link> tag is used to link the external CSS Style Sheet.
The basic structure of the HTML page is shown in the below mentioned figure.