PPC stands for Pay Per Click.
PPC is very popular Internet marketing system used on websites to price online advertisements.
In PPC system, the online advertisers will pay Internet Publishers the agreed upon PPC rate only when an ad is clicked on, regardless if a sale is made or not.
With pay per click system in search engine advertising, the advertiser would typically bid on a keyword phrase relevant to their target market. So, the PPC rate changes depending upon the number of advertisers willing to associate their advertisement with that keyword.
On content websites, the site publisher would usually set a fixed pay per click rate, also called cost-per-click (CPC).
Cost per click (CPC) is the sum paid by an advertiser to search engines and other Internet publishers for a single click on their advertisement, which directs one visitor to the advertiser's website.
Websites that utilize PPC ads will display an advertisement when a keyword query matches an advertiser's keyword list, or when a content site displays relevant content. Such advertisements are called sponsored links or sponsored ads, and appear adjacent to or above organic results on search engine results pages, or anywhere a web developer chooses on a content site.