'Session' or 'Visit' refers to a specific period during which a user actively interacts with a website. This concept is fundamental in web analytics, as it provides insights into user engagement and behavioral patterns on the site.

A session typically begins when a user arrives at the website and continues until the user leaves or remains inactive for a predetermined period (often 30 minutes by default in many analytics tools). Understanding sessions is vital for website owners and marketers as it helps in tracking the number of visits, the duration of each visit, and the user's journey through various pages of the site.

By analyzing session data, website owners can gain valuable insights into how users interact with their content. This includes which pages are most visited, the average time spent on each page, and the sequence of pages viewed. This information is crucial for optimizing website layout, improving user experience, and enhancing the effectiveness of digital marketing strategies.

Furthermore, session analysis plays a key role in conversion rate optimization. It helps in understanding the paths users take before completing a desired action, such as making a purchase or signing up for a newsletter. By studying these paths, businesses can identify and remove barriers to conversion, thus improving the overall performance of the website.