What does the 'S' in HTTPS stand for?

The “S” in HTTPS stands for Secure, identifying Hypertext Transfer Protocol communication protected by TLS encryption.

HTTPS is an extension of HTTP, the protocol browsers use to request and deliver web resources. It places HTTP inside a TLS-protected connection, creating a secure channel over an otherwise insecure network. Earlier systems used SSL, or Secure Sockets Layer, but SSL has been replaced by the TLS family because modern security standards no longer consider the old protocol suitable.

HTTPS provides several protections at once. A certificate helps the browser authenticate the website, encryption helps prevent outsiders from reading the connection, and integrity checks help detect tampering. This is why HTTPS matters for passwords, payments, account sessions, and ordinary browsing—not only for online banking.

The word “secure” does not mean that every aspect of a visit is invisible or that the website itself is trustworthy. Observers may still infer an IP address, port, traffic volume, and sometimes a domain name. HTTPS also cannot make a malicious site honest; it primarily authenticates the server named by its certificate and protects data while it travels between client and server.