Meta Keywords tags - The Meta Keywords tag contribute to your search engine ranking. A meta keyword tag is a brief and concise list of the most important keywords for your page’s content.   

• It is important to keep the list of keywords or keyword phrases down to 10 - 15 unique words. 
• The keywords should be separated by commas (You do not need to leave a space between words separated by commas)
• Words and/or phrases should not be repeated
• The most important word or phrases should be at the beginning of your list.