PPC (Pay per click) marketing is a method of advertising in search engines in order to get a top placement among their sponsored results by paying the bidding amount. It is done by bidding upon different keywords or keyphrases.
In Detail, you decide how much you're willing to pay the search engine company each time someone clicks on your site from a search engine results.
You can bid different amounts according to different keywords that may be used to generate a list of results. The higher your bid for a specific key phrase, the higher your placement will be among the search results when a search is done with that particular keyword.This is the basic of pay per click advertising.