Search Engine Optimisation (SEO) is the process of making your website better for users and Google robots in order for it to rank highly for the keywords associated with your goods and services. The vast majority of Internet users will go straight to a search engine, most probably Google, in order to find the information that they are looking for.
SEO aims to make your website the most relevant on the Internet for the keywords associated with your site and sector, making you rank on page 1 of Google and therefore receive lots of traffic and conversions. There are many aspects to SEO, including on and off page changes that need to be made.
One of the main concerns in the SEO industry at the moment is the inclusion of relevant well-written content as this is what Google is relying on heavily to rank sites after the most recent Penguin update. Having good content, both on page and as links to your site, is required if you are to rank at all; the shift has been made from number of back links to quality.
A common mistake made by SEO companies is making clients websites great for the Google robots to crawl, but not good for the real human user. This results in lots of traffic for the well-ranked site, but few conversions which is not good. Therefore, it is important that the SEO company takes into consideration both important parties and optimises your website with rank and conversion in mind.