docs/data/reusables/enterprise_installation/hotpatching-explanation.md

You can upgrade {% data variables.product.prodname_ghe_server %} to the latest patch release using a hotpatch, which does not require a maintenance window and usually does not require a reboot.

You can use hotpatching to upgrade to a newer patch release, but not a feature release. For example, you can upgrade from 2.10.1 to 2.10.5 because they are in the same feature series, but not from 2.10.9 to 2.11.0 because they are in a different feature series.