Security
security
networking
web
What is Certificate (SSL/TLS)?
Definition
An SSL/TLS certificate is a digital document that binds a domain name to a public key. Issued by Certificate Authorities (CAs), certificates enable HTTPS by proving the server's identity. They contain the domain, issuer, expiration date, and public key.
Why It Matters
SSL certificates are required for HTTPS. Expired or misconfigured certificates cause browser security warnings that drive users away. Let's Encrypt provides free automated certificates. Understanding certificate chains, renewal, and pinning is essential for web operations.