Web analytics involves measuring website data to understand user behavior and optimize the user experience. Goals in Google Analytics define desired user actions like form submissions, duration on site, and page views. Setting up goals allows calculating conversion rates and goal value. Page value metrics show which pages contribute most to goals. Custom segments provide deeper insights into user groups. A/B testing and heat maps help improve conversions and the user experience. Common Google Analytics setup issues include unrealistic bounce rates, self-referrals, missing search keywords, and direct traffic spikes.