Web analytics is the practice of collecting, measuring, and interpreting data about your website visitors. Done well, it removes the guesswork from marketing and product decisions — instead of asking 'what do our customers want?', you can watch exactly what they do on your site and let behavior answer the question.
The most widely used analytics tool is Google Analytics, though alternatives like Plausible and Fathom are popular with businesses that prioritize privacy. All of these tools track the same core set of metrics, so the concepts you learn apply regardless of which platform you use.
Start with traffic metrics. Sessions (total visits), users (unique visitors), and pageviews (total pages loaded) give you a baseline sense of your site's reach. Watch these numbers over time to spot trends. A sudden drop in organic traffic might mean a Google algorithm update affected your rankings. A spike might indicate that a piece of content went viral.
Engagement metrics tell you what happens after someone arrives. Bounce rate is the percentage of visitors who leave after viewing only one page — high bounce rates on blog posts are normal, but a high bounce rate on a landing page designed to convert is a red flag. Average session duration tells you how long people spend on the site. Pages per session tells you how deeply they explore.
Conversion metrics are the most important of all. A conversion is any action you want visitors to take: filling out a contact form, making a purchase, downloading a resource, or signing up for a newsletter. Track your conversion rate (conversions divided by sessions) closely — even a small improvement here can have a dramatic impact on revenue.
Finally, acquisition reports tell you where your visitors are coming from: organic search, paid ads, social media, direct traffic, or referral links from other websites. Understanding your traffic sources helps you invest in what's already working and fix what isn't.