Advertising is a paid communication to inform and influence potential customers about a product or service, with objectives including informing, persuading, and reminding. It utilizes various media such as print, broadcast, outdoor, and digital avenues, offering advantages like brand building while also posing disadvantages like increased costs and potential misleading messages. Personal selling, as a more direct method, involves face-to-face interactions, allowing for customized approaches to meet customer needs but is often more costly and slower in process.