Search Engine Optimisation (SEO) refers to the optimisation of websites/webpages for search engine indexing and quality determination. In practical terms for owners of websites, it means that your website can be designed (design here includes the content it hosts) in such a way that a search engine (SE) will regard it as a quality site. The quality of your site in turn will affect its position with regards to search result rankings: the better a site is the higher up the results ranking it should appear.
Google uses about 200 parameters in assessing a webpage’s quality, and this assessment is vital when it returns results for search terms. The value of SEO should not be under-rated: if traffic to a site is determined by the visibility of the site on the internet, having it appear at or near the top of the rankings will be fundamental to the success of the project. Research has shown that the organic search engine rankings (organic refers to natural SE results rather than the adverts that appear at the top and side of the results page) generate the majority of site traffic. To restate this, the higher a webpage’s search engine ranking, the more traffic is directed to that site from the search engine provider. Company’s like Google try to assess a webpage’s quality in order to give their patrons the best user experience possible. End users, like myself, get quite frustrated when a page that is returned in a search turns out to be quite unrelated to the search, and by extension, quite useless for my intended purposes. If, for example, I’m looking for a Mercedes Benz B class for sale, I trust my search engine to return good, usable results.
Google’s logic is that I, as an end user, will be tempted to try another search engine to obtain better results. In this they’re probably right, and much of Google’s current success owes to the fact that it developed the PageRank quite early in its history. The PageRank is an information assessing process that yields an estimate of a webpage’s quality based on a set of predefined criteria. It is named after Larry Page, one of Google’s co-founders.
Search engines will look at a wide variety of elements when judging a webpage. The central general advice issued by search engine operators is that a site should contain original, high quality content. Over and above this, the site can be designed (in terms of its architecture) in such a way that it will be search engine friendly (which, by extension, is indicative of quality). It is important to remember that the more specific a webpage is, the better: it is good practice, for example, for a webpage to have a well-defined topic/theme that the content sticks to without too much digression. If this is achieved, a search engine will note that it contains a high portion of relevant information which in turn will better its quality assessment. It is, however, important not to over-stock the webpage with repetitive keywords. The software engineers at search engine companies have designed the quality determination process in such a way as to identify normal linguistic patterns contained in speech and writing, and will therefore quickly detect if a page has an unnaturally high amount keywords. With this said, it is also important to bear in mind that your page must contain some keywords that would probably be used by an end-user when searching for a site of the type you provide: for example, if you sell kitchen appliances, it is necessary that your site rank well for the aforementioned search term.
There are agencies that specialise in SEO for websites, and if you would like traffic to be directed to your site from search engines, it would be a good idea to bear in mind that SEO forms an important part of the marketing mix.