Simply explained, it is the technique of attaining a high ranking in search engines and directories via changes to your site code to make it more search engine optimization compatible. It different than link building services and directory submission
Did you know that most search engines can’t “read” graphics? Did you also know that key search words and phrases in your “title tag”, “META tags” (in the HTML script of your site) and body text are often very important references that search engines analyze when ranking web sites for search relevancy? Optimizing your title tags, meta tags and your body text for search engines gives it a much better chance of ranking highly for particular words or phrases that you would expect potential visitors to type in to search engines to find your site.
For example, if you are a Miami florist, you should have logical search phrases such as “flowers”, “Miami florists”, “bouquets Miami” and even target search terms such as “Miami weddings”, “Valentine’s Day gifts” etc integrated in your title and meta tags, as well as in the visible text of your site. That way, if anyone types in those phrases in a search engine, your site is more likely to appear higher in the search results.