The Title Tag
The Title Tag should contain your MOST important searchable keywords and be 60 characters or less in length.
Tip: Keywords found in the Title Tag have the highest ranking value with most all search engines. The 60 character limit is because not all search engines are created equal. Some search engines will only display a maximum of 60 characters of text for a Title in their search results. Having your page Title cut off by some search engines is not what we consider "search engine friendly".
The Meta Description Tag
The Meta Description Tag should contain a brief description of what can be found on the current page and be 150 characters or less in length.
Tip: Take time to create a keyword rich Meta Description Tag. This can increase your search engine rankings and some search engines will highlight search terms found in their search results helping your listing to stand out from others. Not all search engines display the Meta Description Tag every time, but most all major search engines (including Google) do utilize and display the Meta Description Tag in their SE results. The 150 character limit is because some search engines will only display a maximum of 150 characters of text for the description in their search results. Keeping your Meta Description Tag under 150 characters helps insure your description makes sense to those who view it.
The Meta Keywords Tag
The Meta Keywords Tag should contain ONLY keywords which are also found in the viewable text on the page and be 874 characters or less in length (less is better).
Tip: The Meta Keywords Tag is not as important as it once was and many search engines no longer index words found here. The Meta Keywords Tag can increase your search engine rankings when constructed properly. The 874 character limit is a calculation based on the storage ability of most search engines. But this does NOT mean you should enter 874 characters here. In fact, you will likely suffer from "keyword saturation" if you do. Your Web page's Keyword Density calculation is probably the most important consideration when optimising your Web pages. Having a lot of keywords here can destroy your keyword densities and your SE rankings so be careful.