Meta tags are HTML (Hyper Text Markup Language) commands or directives which play an important part in SEO (Search Engine Optimization) and web site designing. They are not visible on a page displayed on any browser like Mozilla Firefox, Microsoft internet explorer. Only contents of one tag (Title) are displayed on top row of the browser and another “description” is sometimes displayed in search engine results.
Meta tags are basically used to provide information about contents on a web page to browsers and search engines. Contents of description meta tags are used by search engines to give an idea about the contents of a website when someone types a related keyword for which the web page ranks well and your site is displayed in listing, contents of meta tag description is displayed which contains brief overview of contents on your web page or web site.
All META TAG directives should be placed after head declaration and before the start of body section. Most of these tags which are said to be important for search engine optimization of a web site or web page are optional i.e. you may or may not choose to use them and decide which one to include and which to omit. If you do not use meta tags then it does not mean that it is not good for the health of your website or it can affect appearance of your website or increase time it takes to load a web page but use of meta tags has certain advantages which one cannot afford to ignore. As a rule of thumb you should include at least three of them i.e. title, description and keywords as they play important role in search engine optimization and inclusion of your web site in directories.
Basic Meta Tags for Search Engine Optimization and Website Indexing
1. Title: This is the first meta tag used to display title of your web page in a browser. You should place contents of title meta tag between. Contents of this tag must be short and targeted. Number of characters it can contain varies from search engine to search engine. Normally it should be in between 40 to 80 characters.
2. Description: This is an important declaration and its contents are displayed in search results along with URL of your web site. A good description can bring more visitors to your web site. It is used like this: Length of description meta tag should be in between 80 to 150 characters.
3. Keywords: This meta tag is purely for search engines and directories. It plays an important role in search engine placement of your site. A lot of planning and research is required to find effective keywords. Keywords should be placed one after another and separated using a comma & space. Keywords must be the words that do appear on your web page or the contents of the web page are related to it. Providing a list of keywords for search engines do not mean that they will include any or all of them. The length of keyword meta tag should be in between 150 to 300 characters. More options are:
4. Revisit : This provide direction to robots about there next visit which means when can they expect some changes in contents, structure of the web page.
5. Index, Follow : This is an important meta tag which tells robots whether to index the current page or not (using index or noindex) and whether to follow links pointing to other internal and external resources or not (using follow or nofollow). Most websites use the pair (index, nofollow) to include that page in there index and instruct not to follow other links on the page, this is used to protect page rank and avoid it distribution to other sites.
6. Update frequency: This is similar to revisit tag and provides a hint about frequency of updates.
7. Author: This can be used to provide name of the content owner explicitly to robots.
8. Language: This provides information about the language of the contents which helps both the browser (to display page contents in that language) and search engines (to index page in relevant language directory).
Use of most HTML meta tags in your website or web pages is optional i.e. you may or may not choose to use them. Which to include and which to omit depends on your choice or requirements of your website for optimization. As a rule of thumb you should include at least three of them i.e. title, description and keyword meta tags in order to make your website visible to search engines.
There are a number of options and uses which are customized by webmasters and website designers to provide additional information to robots or for there own records.