Search Engine Optimization (SEO) is used in all aspects of web marketing. You need to understand as much as you can about how SEO works in order to get the proper marketing of your website online.
When you use SEO in all of your content - both text and visual, you can draw more traffic to your site. In order to understand how to use SEO, you need to know why people use this type of marketing and rely on it so heavily in order to get the desired traffic to their website. SEO is what gets a website noticed in the search engines.
So what exactly is SEO? This sets up your text, photos and videos so that they are easy to find when someone is searching for them using the various search engines online. While it is often said that Google relies more on SEO content than Yahoo, which relies more on link building, the truth of the matter is that in order for a website to be discovered online, it must come up in the search engine.