The ARF Internet model, also known as the Advertising Research Foundation Internet model, is a framework used to measure the effectiveness of online advertising campaigns. It consists of four key stages: Awareness, Relevance, Favorability, and Action. This model helps businesses understand how their online ads are impacting consumer behavior and allows them to make data-driven decisions to optimize their advertising strategies. By analyzing each stage, the ARF Internet model provides valuable insights into the success of online advertising efforts, ultimately leading to more targeted and impactful campaigns.