HTTPS, short for Hypertext Transfer Protocol Secure, is the encrypted version of HTTP and the standard protocol for transferring data securely between a web browser and a server. When you visit a website with HTTPS in the address bar, all data exchanged between your device and that server is encrypted, meaning it cannot be read or tampered with by a third party intercepting the connection.
The security in HTTPS is provided by TLS, or Transport Layer Security, which replaced the older SSL (Secure Sockets Layer) protocol. Despite SSL being largely retired, the terms SSL and TLS are still used interchangeably in everyday speech, and the digital certificates that authenticate HTTPS connections are widely referred to as SSL certificates. In technical terms, what happens is a handshake: the browser and the server agree on an encryption method, the server presents its certificate, and a secure session is established before any actual data is sent.
The certificate itself serves two purposes. First, it enables the encryption. Second, it verifies identity. A valid certificate is issued by a trusted Certificate Authority and confirms that the server you are connecting to is genuinely who it claims to be. This protects users from impersonation attacks, where an attacker might otherwise redirect traffic to a fraudulent site that looks identical to the real one.
From a practical standpoint, HTTPS matters for every website that handles user input, whether that is a login form, a contact field, a payment page, or anything in between. Without HTTPS, data submitted through such forms travels as plain text and is vulnerable to interception. With HTTPS, that same data is unreadable to anyone without the correct decryption key.
The significance of HTTPS has grown well beyond security-conscious websites. Major browsers now flag HTTP connections as "not secure," and search engines treat HTTPS as a ranking signal. This means that HTTPS is no longer optional for websites that want to be taken seriously, both by users and by the algorithms that determine visibility in search results.
For developers and site owners, enabling HTTPS requires obtaining a TLS certificate and configuring the server to enforce encrypted connections. Free certificates are widely available through services such as Let's Encrypt, removing the cost barrier that once made HTTPS a more complex undertaking.
HTTPS is the foundation of trusted communication on the web. It does not guarantee that a website is legitimate or safe in every sense, but it does guarantee that the connection to it is private and authenticated.