Security
SAN
Abbreviation for Subject Alternative Name
In short and in plain language
SAN is a list of extra web names.
It sits in a certificate. So one certificate can cover many sites of a firm.
That can make upkeep easier.
Definition
SAN designates the list of additional domain names that a single TLS certificate can cover. A certificate with this field can include several domains and subdomains of a business. This can simplify certificate management.