SEO stands for Search Engine Optimization, which is the practice of increasing the quantity and quality of traffic to your website through organic search engine results.
Proper utilization of SEO techniques you can help you achieve the following benefits:
Quality of traffic. You can attract all the visitors in the world, but if they're coming to your site because Google tells them you're a resource for Apple computers when really you're a farmer selling apples, that is not quality traffic. Instead, you want to attract visitors who are genuinely interested in the products that you offer.
Quantity of traffic. Once you have the right people clicking through from those search engine results pages (SERPs),more traffic is better.
Organic results. Ads make up a significant portion of many SERPs. Organic traffic is any traffic that you don't have to pay for.
You can also refer to the “What is SEO” blog by Moz for in-depth details regarding SEO, its advantages, how it works and more.