A session is defined as a group of interactions one user takes within a given time frame on your website. Google Analytics defaults that time frame to 30 minutes. Meaning whatever a user does on your website before they leave equals one session.

The session of activity that a user with a unique IP address spends on a Web site during a specified period of time.

A "session" generally refers to a period of time during which a user interacts with a website, application, or service. It's a way to track and manage user activity, often used for authentication, personalization, and remembering user preferences.