Metrics are measures or indicators that are used to evaluate the performance of a system, process, or activity. In the context of advertising, metrics are used to evaluate the effectiveness and efficiency of advertising campaigns, and to provide insights into the performance and impact of ads. Advertising metrics can take many forms, such as clicks, impressions, conversions, engagement, or reach, and can be used to measure the performance of individual ads, channels, or campaigns. Advertising metrics are an important tool for advertisers, as they can provide insight into the effectiveness and efficiency of their advertising efforts, and can help them to make data-driven decisions about their campaigns.