Paid advertising also known as PPC (pay per click), refers to online advertising where a business pays the search engines an amount of money per click i.e. when the searcher clicks through to the business’s website or landing page.
The amount payable to the search engines, with Google being the market leader, is arrived at as a result of an auction process with different businesses bidding on Keywords or phrases. It should be noted that the business that bids the most does not always achieve the top ranking as Google’s algorithm also factors in such items as relevancy and quality when presenting results to a searcher.
Google’s Keyword Planner is used when researching the Keywords that the business is willing to bid on. This makes sense as the phrases that a potential customer might search when looking for a business like yours will be the same for both SEO and PPC campaigns.