How does Ad Rank affect cost per click (CPC)?

When it comes to CPC (the actual amount you're charged per click), the most you will end up paying is the minimum amount required to hold your ad position. In the Search Network, ads that appear above the search results generally have a higher CPC than those that appear below the results.

It is used to determine your cost per click (CPC) and multiplied by your maximum bid to determine your ad rank in the ad auction process. Your Quality Score depends on multiple factors, including: Your click-through rate (CTR). The relevance of each keyword to its ad group.