What is sessions in google analytics?

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 (e.g. browses pages, downloads resources, purchases products) before they leave equals one session. In short, the Sessions metrics is a unified way to report "Visits" and "Active Users."

A session can be defined as a group of interactions that takes place on the website within a given frame of time. For example, a single session can comprise of multiple screens or page views, events, social interactions, and e-commerce transactions.

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 (e.g. browses pages, downloads resources, purchases products) before they leave equals one session.