HTML Meta Tags

HTML lets you specify metadata - information about a document rather than document
content -in a variety of ways. The META element can be used to include name/value
pairs describing properties of the HTML document, such as author, Expiry Date, a
list of key words, author etc.

The  tag is an empty element and so does not have a closing tag, rather,
 tags carry information within attributes, so you need a forward slash
character at the end of the element.

Metadata provided by using meta tag is a very important part of the web. It can
assist search engines in finding the best match when a user performs a search. Search
engines will often look at any metadata attached to a page - especially keywords -
and rank it higher than another page with less relevant metadata, or with no metadata
at all.

Adding Meta Tags to Your Documents:

You can add metadata to your web pages by placing  tags between the  and
 tags. The can include the following attributes:

Attribute	Description
Name	Name for the property. Can be anything. Examples include, keywords, description, author, revised, generator etc.
content	Specifies the property's value.
scheme	Specifies a scheme to use to interpret the property's value (as declared in the content attribute).
http-equiv	Used for http response message headers. For example http-equiv can be used to refresh the page or to set a cookie. Values include content-type, expires, refresh and set-cookie.

NOTE: Core attributes for all the elements are discussed in next chapter.

Meta Tag Examples:

Let's see few important usage of Meta Tags.

Specifying Keywords:

We specify keywords which will be used by the search engine to search a web page.
So using following tag you can specify important keywords related to your page.

Document Description:

This is again important information and many search engine use this information as
well while searching a web page. So you should give an appropriate description of
the page.

Document Revision date:

This information tells about last time the document was updated.

Document Refreshing:

You can specify a duration after which your web page will keep refreshing. If you
want your page keep refreshing after every 10 seconds then use the following syntax.

Page Redirection:

You can specify a page redirection using Meta Tag. Following is an example of
redirecting current page to another page. You can specify a duration after which
page will be redirected.

If you don't provide a duration then page will be redirected immediately.

Setting Cookies:

You can use Meta Tag to store cookies on client side later information can be used
by then Web Server to track a site visitor.

If you do not include the expiration date and time, the cookie is considered a
session cookie and will be deleted when the user exits the browser.

Setting Author Name:

You can set an author name in a web page using Meta Tag. See an example below:

If you do not include the expiration date and time, the cookie is considered a
session cookie and will be deleted when the user exits the browser.