SEO is short for search engine optimisation, it is the process by which you get a website to appear near the top of the search results for the terms that you want to rank well for. The reason that you would want to do this is obvious, the site that is at the top of the search results will get the most visitors. A site that is on the tenth page of the search results however will likely get very few visitors. Therefore if your webpage is an important part of your business you have to make sure that it ranks well.
The search engines are supposed to provide the most relevant results for each search term and this is what they try to do. Therefore in theory you should be able to get your site to rank at the top of the search results simply by providing the best and most relevant content. In practice things don’t work out that way, most of the time you are going to have to take steps to help your site to rank well. How much work is required will depend on how much competition there is for that search term.
There are basically two parts to search engine optimisation, the first is known as on page optimisation. This involves making sure that it is clear what your site is about. The easier it is for the search engines to tell what your site is about the easier it will be for it to determine what it should rank for. That means that you are going to want to make sure that your content is tightly focused. You will also want to make sure that your site is laid out in a way that is easy to navigate and that related pages are linked together.
The other part of SEO is off page optimization, this is mainly about getting links. Since the search engines really can’t make judgments on things like quality it is necessary that there be another way to determine which sites are best. In large part this is done by looking at how many other sites link to your site. The theory is that the best sites will be linked to the most. This also makes it possible to get your site to rank well by creating the links yourself. Not all links count for the same value so it is important that you know which links are the most useful and that you go after them.
It is important to realise that SEO is not a onetime thing, if you stop doing it you can be sure that other sites will go past you in the rankings. That means that you will need to be constantly adding new links to your site. Once you have your site ranked at the top you can reduce the amount of time that you have to spend looking for links but you can’t stop entirely.
Taken from: http://www.gnctech.net/what-is-seo.php