An SSL/TLS certificate is a digital credential that authenticates a website's identity and enables encrypted connections between a user's browser and the website. This encryption protects sensitive information, such as passwords and credit card numbers, from being intercepted by malicious actors. SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) are protocols that ensure data privacy and integrity during transmission. When a website has a valid SSL/TLS certificate, users see a padlock icon in their browser's address bar, indicating the site is secure. These certificates are issued by trusted Certificate Authorities (CAs) and are essential for building trust and ensuring safe online transactions.