ESM is short for "Expanded Security Maintenance". This tag should only be used for questions about how to activate and configure an Ubuntu Pro subscription to allow for ESM updates. Please note that questions about Ubuntu releases past the 5-year LTS period (but in the 10-year ESM period) are OFF-TOPIC for this site.
ESM (Expanded Security Maintenance) is the terminology used by Canonical for the commercial subscription that offers 10 years of security patches for applications in the main
and universe
repositories, instead of the usual 5 years granted by LTS releases.
ESM is a part of the ubuntu-pro subscription, and Canonical refers to applications covered by this subscription as "ESM Apps".
Canonical information about ESM.