Glossary · Hosting and delivery
SSL certificate
A digital certificate used during TLS to authenticate a website name and establish an encrypted connection.
Also called: TLS certificate, HTTPS certificate
Definition
A website certificate connects a public key to a hostname through a trusted certificate authority. Browsers validate it during the TLS handshake before using encrypted HTTPS communication.
Why it matters
Expired, misconfigured, or mismatched certificates can block visitors and undermine trust even when the website files are healthy.
Common misunderstanding
A certificate protects data in transit; it does not prove the business itself is trustworthy or make the application immune to compromise.
Related terms
Related system family: Hosting & Release
Sources
- HTTP (opens in a new tab) · MDN Web Docs
Last reviewed July 16, 2026