HTML Documents are files which use HTML elements for creating it. HTML elements are defined using HTML tags. See the following HTML code:
<title> Write down the page tile</title>
Here you can write what ever information you want to share<b> this text bold </b>
In above code HTML element starts with HTML tag : <b>. The content of the HTML element is : the text is bold. The HTML elements ends with an end tag like </b>. And next the HTML elements starts with HTML the start tag <body> and end with HTML end tag </body>.
the purpose of the <body> tag is to define thew HTML elements that contains the body of the HTML documents.