When a search engine delivers the results of a query to a user, it ranks these results according to an algorithm. The search engine's algorithm is an advanced mathematical equation that tells the search engine how to order the results from its database that match the user's query.

For example, in a very simple algorithm, we might have 3 input factors - age, keyword density & keyword placement. The newer a page, more dense its keyword usage & closer to the top of the page the keyword placement, the higher it would appear in our results. Written in mathematical form, the algorithm would look something like:

Ranking = 0.30(Age) + 0.40(Keyword Density) + 0.30(Keyword Placement)

This highly simplistic example is illustrative of how a ranking algorithm operates. Each value is assigned a weight - the numbers preceeding the input. These weights, combined with the values of each input give us a ranking number. This number is calculated for each of the relevant results in our index to the specific query and the results are displayed from highest to lowest.

By looking at how an algorithm is constructed, we can easily see how someone with knowledge of its structure could exploit that knowledge to gain top positions for their desired keyword phrases. This is the practice of SEO - search engine optimization. Although none of us have the exact information about what elements go into the search engines' algorithms, we can surmise what those pieces are and how important they are to ranking well. By applying that knowledge, we can help to boost the position of our web site in the rankings.

The optimization process is lengthy, tedious and at time exceptionally frustrating. But, with a careful approach and the right knowledge, you can begin optimizing your site to appear higher in the search results at he major engines.