From http://www.w3schools.com (Copyright Refsnes Data)

HTML 5 <head> tag

Definition and Usage

The head element can contain information about the document. The browser does not display the "head information" to the user. The following tags can be in the head section: <base>, <link>, <meta>, <script>, <style>,  and <title>.

Differences Between HTML 4.01 and HTML 5

The profile attribute is no longer supported in HTML 5

Tips and Notes

Always specify a title for the document!

Example

Source
<html>

<head>
<title>Title of the document</title>
</head>

<body>
...
...
...
</body>

</html>

Attributes

Attribute Value Description 4 5
profile URL A space separated list of URL's that contains meta data information about the page 4  

Standard Attributes

class, contenteditable, contextmenu, dir, draggable, id, irrelevant, lang, ref, registrationmark, tabindex, template, title

For a full description, go to Standard Attributes in HTML 5.

Try-It-Yourself Demos

The title of a document
The title information inside a head element is not displayed in the browser window.

One target for all links
How to use the base tag to let all the links on a page have the same target.

Styles in HTML
How to format an HTML document with style information added to the <head> section.

Link to an external style sheet
How to use the <link> tag to link to an external style sheet.

Document description
Information inside a meta element describes the document.

Document keywords
Information inside a meta element describes the document's keywords.

From http://www.w3schools.com (Copyright Refsnes Data)