The head of an HTML document is an unordered collection of information about the document. It requires the <TITLE> element between <HEAD> and </HEAD> elements thus :

<HEAD>
<TITLE> Introduction to HTML </TITLE>
</HEAD>

The <HEAD> and </HEAD> elements do not directly affect the look of the document when rendered.

The following elements are related to the head element. While not directly affecting the look of the document when rendered (apart from the <STYLE> element Style Sheet declarations), they do provide (if used) important information to the HTML user agent.

<BASE> - Allows base address of HTML document to be specified
<ISINDEX>- Allows keyword searching of the document
<LINK>- Indicate relationships between documents
<NEXTID>- Creates unique document identifiers
<TITLE>- Specifies the title of the document
<META> - Specifies document information useable by server/clients
<STYLE> - Used by browsers that support use of style sheets to specify styles within the document

NOTE : The Title element is the only element described here that is required as part of the Head of a HTML document for conformance to any HTML standard.

<HTML> Document Structure Elements Overview <BASE>