What is search engine optimization?
In the simplest terms, search engine optimization (SEO), is the process of making your website visible to search engines (i.e. Google, Bing, DuckDuckGo, etc.). Given the amount of websites out there, and the number of users looking for businesses via search engines, SEO is imperative to online success.
Short answer: bots. Yes, bots run the internet, basically. Since there is so much content on the world wide web, Google, Bing, and the others use bots that check out (crawl) your website to determine what content is on it, and based on the user and their search query, the bot determines if your site is a good fit.
In contrast with PPC advertising, SEO will drive traffic to your site organically. In this case, organic is a fancy term for FREE. So, with an effective SEO strategy, you can spend less money on advertising, and get better returns over time. This is why SEO can be a major contributor to getting (or keeping) your company in the black!