What is SSL/TLS certificate?

A certificate that proves a site's identity and enables HTTPS encryption.

Certificates list the names they cover (SANs), the issuing authority and a validity window. Public certificates now last at most 398 days, and the industry is moving to much shorter lifetimes, so monitoring expiry matters.

Related terms

• BIMI: Brand Indicators for Message Identification: shows a brand logo next to authenticated email.
• Certificate Transparency: Public, append-only logs of every certificate issued by public authorities.
• robots.txt: A file at the root of a site telling crawlers which paths they may fetch.