Running User

See the answer below.

Determines the level of access to the dashboard data.

In Salesforce, a "Running User" is a user account that is used to determine the level of access that a dashboard, report, or automation should have when it runs.

For example, if a dashboard is set to run as a "specified user", that user's access permissions will determine which data is displayed in the dashboard. If the dashboard is set to run as a "running user", then the access permissions of the running user will be used instead.

The running user can be set at the time of creating a report, dashboard or other automation or can be changed later. The running user is typically used when the user viewing the dashboard or report doesn't have the necessary access permissions to view all the data.

It is important to choose the right running user for your automation, as it can greatly impact the data displayed and the actions that are taken. Typically, the running user is set to an administrative or high-level user account that has access to all the necessary data.