What is an SSL certificate, and why does a website need one?

An SSL certificate, more accurately used with TLS, helps a browser establish an encrypted connection to a website. It proves that a trusted certificate authority issued the certificate for the requested hostname and allows traffic to travel without being readable or modified by ordinary intermediaries on the network.

HTTPS protects login details, form submissions, cookies, payment handoffs, and the pages visitors read while data travels across the network. The site’s trustworthiness and resistance to malware still depend on application updates, access control, safe code, backups, and responsible handling of stored data.

The certificate must cover every hostname visitors use, remain within its validity period, and be served with the correct intermediate certificates. The server also needs a matching private key. Modern hosting platforms often automate issuance and renewal through a certificate authority such as Let’s Encrypt.

After installation, redirect HTTP to HTTPS and update internal resources so pages do not load scripts or images over an insecure connection. Monitor renewal and test the public certificate from outside the hosting network. An expired or mismatched certificate can block visitors even when the website itself is running normally.