There are hundreds of factors in the Google algorithm and the algorithms of the other search engines that determine where your site is placed. A Search Engine Optimizer understands these factors and knows how to make your site look favorable and important to Google. There are on-site and off-site factors to SEO. The on-site factors generally increase relevance to your site, while the off-site factors increase relevance and importance.

Basic on-site SEO covers optimizing titles, meta tags, headers and page content. For non-competitive terms, this is generally enough to get you ranking well. Competitive terms generally require better on-site optimization which requires use of latent sematic terms (related keywords), page rank funneling, use of cannonical redirects, use of alt text tags, URL optimization, implementation of an XML sitemap and much more.

The more competitive a keyword gets, the more imporant off-site SEO becomes. Most off-site SEO is generally refered to as “link building.” Link building involves getting inbound links from other sites. There are a variety of different ways to do this, but it is important to do link building in a search engine friendly manner. In order to make link building effective it should look natural to Google and the other search engines. Generally, the more links you have, the better, but there is a big quality difference between links. A link from an untrusted spammy site provides zero benefit, but a link from a well-trusted popular site can be more powerful than 1,000 low quality links.