If you are completely new to this, SEO stands for Search Engine Optimization.
SearchEngineLand.com has an excellent description that I really like.
"SEO stands for “search engine optimization.” It is the process of getting traffic from the “free,” “organic,” “editorial” or “natural” search results on search engines." In other words, how to come up on the Google search results. In this short article I will cover one of the most effective ways to rank up on Google.
Lets suppose for a second that you are looking for a good developer to work with. One of your friends tells you that their brother-in-law is a developer. You also find a random developer online. At this point, are you more likely to go with the random developer or the referral? Most people would go with the referral. This is what backlinks are. If other websites have links pointing to your website, then the search engine will see that as a referral. This will get you a lot of positive points in the eyes of Google and help you show up and rank better on search results. The more websites you have telling people to go to your website, the better you are in the eyes of Google.