SSL Certificate
A digital certificate that authenticates a website's identity and enables encrypted connections.
Definition
An SSL (Secure Sockets Layer) certificate is a digital certificate that verifies a website's identity and encrypts data transmitted between the site and users' browsers. SSL enables HTTPS connections, indicated by the padlock icon in browser address bars.
SSL certificates are issued by Certificate Authorities (CAs) after verifying the requester's identity. Certificate types range from domain validation (basic encryption) to extended validation (comprehensive business verification). Let's Encrypt has made basic SSL certificates free and automated.
Why It Matters
SSL is now essentially required for all websites. Browsers warn users about non-HTTPS sites; Google uses HTTPS as a ranking signal; users expect the padlock icon. Beyond security, SSL is a basic trust signal.
For e-commerce and any site handling sensitive data, SSL is legally and practically essential for protecting user information.
Examples in Practice
A site's migration to HTTPS eliminates browser warnings that were deterring visitors and hurting conversions.
An e-commerce store uses extended validation SSL, displaying their verified company name to build trust during checkout.
Automated SSL certificate management through Let's Encrypt reduces certificate expiration incidents that previously caused outages.