If a user visits a web page with an embedded video, leaves without clicking on anything, and the session times out, how will Google Analytics report the session?

A bounce is a single-page session on your site. In Analytics, a bounce is calculated specifically as a session that triggers only a single request to the Analytics server, such as when a user opens a single page on your site and then exits without triggering any other requests to the Analytics server during that session. Events are user interactions with content that can be tracked independently from a web page or a screen load. Tip: It's important to keep in mind that any implementation of Event Tracking that automatically executes on page load will result in a zero bounce rate for the page.