What is the difference between metrics and dimensions in analytics?

Metrics are quantitative measurements (conversion rate, page views, revenue), while dimensions are attributes that describe data (country, device, traffic source, page). Metrics answer 'how much' or 'how many', while dimensions answer 'what', 'where', or 'who'. You combine dimensions and metrics to analyze data—for example, conversion rate (metric) by traffic source (dimension). Understanding this distinction helps you ask better questions and analyze data effectively. Example: Analyzing conversion rate (metric) by device type (dimension) revealed mobile conversions were 50% lower, leading to mobile optimization efforts.