The term Search Engine Optimization does have two parts one of which is on-page optimization, which means all methods and opportunities that the content and structure of a web site can be performed. And the other is the off-page optimization of which relates to the popularity of your site outside your own. With off-page optimization you will need to improve your link popularity and link to related quality sites as this is part of the algorithm of most search engines when they rank your website to a specific keyword. Though algorithm often changes as to improve the results and take out those factors that are being abuse by websites that wants to rank their sites immediately and not consider the visitors of their websites.
To investigate Web sites on their respective potentials, free online tools can be used. Many sites in the internet provide SEO services, but from that many sites I only suggest to choose SEOP.com. Why I suggest SEOP.com to you? It is because SEOP.com is safe and also legal SEO. So visit this site now.