Group Policy execution is processed in the following order: local--site--domain->ou.
The same policy, the computer Configuration takes precedence over the user configuration.
Group Policy also periodically refreshes GPOs, ensuring that Group Policy applies new and changed GPOs instead of waiting for the computer to restart or the user to log off. The time period between these refreshes is called the Group Policy refresh interval, which is 90 minutes by default, plus a small set of built-in random times to prevent all computers from flushing at the same time. If you change the GPO in the middle of the day, Group Policy applies the changes within about 90 minutes. There is no need to wait until the end of the day, when the user logs off or restarts their computer. In advanced scenarios, you can change the default refresh interval.
Ad Group Policy something (processing order)