When you optimize your website, a great deal of factors are taken into consideration by the search engines. Some are based on the keywords that you use. These factors include things like links, site design, navigation, etc. Today, the term's SEO and SEM are frequently used interchangeably. SEM refers to Search Engine Optimisation, while SEO stands for Search Engine Marketing. It is important to understand that SEO is also a tool which can be employed to improve the sales performance of your site.