Web, domains and email
ACME
Abbreviation for Automatic Certificate Management Environment
In short and in plain language
ACME is an open set of rules for servers.
With it, they get certificates on their own. They also renew them by themselves. These certificates are for coded links.
So nobody has to do the renewal by hand. This can help to stop outages. Such outages come when a certificate has run out.
Definition
ACME is an open protocol that lets servers request and renew certificates for encrypted connections automatically. This way nobody has to trigger the renewal by hand. It can help to avoid outages caused by expired certificates.