The aim of SEO is to make a website easy for both users and search engines such as Google to understand. While search engines have become much more sophisticated, they still can’t “see” and understand a web page the same way a person can.
For example, if you posted a picture of some flowers online a person might describe it as a “picture of beautiful red roses in a porcelain vase”. A search engines doesn’t have this ability, it just detects that there’s an image file present. Fortunately, using SEO techniques, webmasters can provide signals that search engines can use to understand content, both written and visual.
SEO attempts to ensure that your website gives the right signals to the search engines so that the site is returned high in the results pages when someone searches for particular search terms. The relative position of these search results is a crucial factor in how many people visit your site.
This graph shows the % of people who click through based on search result position.