Both pay-per-click and SEO are targeted to get your website placed as close to the top of search engine results as possible. One of the differences is that it takes minutes to set up a pay-per-click campaign versus months for a good SEO campaign.
Pay-Per-Click is a simple type of paid advertising that most search engines, including some of the largest ones, now offer. It requires a bid for a "per-click" basis, which translates to your company paying the bid amount every time the search engine directs a visitor to your site. There is the added bonus that when a per-click site sends your website traffic, your site often appears in the results of other prevalent search engines.