docs/data/reusables/codespaces/inactivity-definition.md

In the context of the {% data variables.product.prodname_codespaces %} idle timeout, inactivity is defined as the absence of activity indicative of a user's presence. Personal interaction with a codespace, such as typing or using the mouse, resets the idle timeout period. Terminal activity, either input or output, also resets the idle timeout period. For example, if you publish a web app on a port from a codespace and page requests generate output in a terminal on the codespace, then each time terminal output occurs the timeout will be reset. However, if you share a port, and then don't interact with the codespace, and no terminal output is generated, the codespace will time out after the configured period.