SEO stands for Search Engine Optimization and PPC stands for Pay Per Click.  SEO is a technique to help optimize your solar installation website to appear higher in a search engine results for a given search query.  These are also called “organic” results.  PPC is a type of paid advertising on the Internet where you pay to place your marketing message.  You only pay if someone clicks on your ad.  These are called “paid” results.

For more detailed information on organic SEO vs paid search, check out this article on SEO Kings.