Cost Per Click (CPC) is a crucial aspect of online marketing, indicating how much advertisers pay when users click on their ads. It's an essential tool for managing ad spend and understanding campaign effectiveness. CPC directly impacts cost-efficiency, budget planning, and performance tracking. Bids are placed on keywords, with final CPC determined by bid value, ad relevance, and quality. Factors such as keyword selection, bidding strategies, and quality score affect CPC. Optimizing CPC requires refining keywords, improving ad quality, A/B testing, and controlling budget allocations.