An SEO agency provides Search Engine Optimization (SEO) services. These services are designed to optimize a particular website for the search engines such as Google which in turn allows them to be ranked highly. This means that when a person types a phrase into their web browser, the sites returned are ranked in order of usefulness and relevance. It follows that the best sites achieve rankings at or near the first page and to do this site has to be optimized correctly.
Search Engine Optimization is a specialized skill and is conveniently divided into two areas; "on page" optimization and "off page" optimization.
On page optimization looks at the structure of a site and the way the links are constructed. Engines such as Google "crawl" a site using sophisticated robots and these look at the structure of a site and what phrases are used as keywords, particularly in titles and headings. Some platforms provide a structure that is attractive to the search engines and it can be advantageous to use such web building tools – these include the very popular WordPress and also PHP coded sites.
Off page optimization looks at increasing the popularity and relevancy of a site. The best way to do this is to ensure there is a large number of backlinks. Backlinks are simply links on other sites that link back to your site. The more of these there are and the more important the site from which they point, the higher a site is ranked. Importance of a site is usually measured using something called Page Rank. This is a number from 1 to 10 and the higher the number the more important the site in the eyes of a search engine. Very popular sites such as eBay have a high page rank and minor sites have a very low page rank.
Another method of increasing a sites visibility to the search engines is to ensure that a "ping" is sent to the search engines whenever a site has new content. The ping is simply an electronic signal which effectively tells the search engines that a site has been updated. The search engines then re-crawl the site and discover the new content.