SSL stands for Secure Sockets Layer. It is a protocol that was designed to keep communication over the internet safe. Data sent via an SSL connection is protected by a mechanism called encryption that prevents eavesdropping and tampering.
SSL is an industry standard and is used by millions of websites to protect online transactions with customers. Anyone who visits a website knows if the site has a valid SSL certificate by looking for a Green Padlock icon on the web browser.
Some SSL certificates can turn the address bar of the browser green to visually increase customer's confidence. Also, the URL of any website using SSL starts with HTTPS:// instead of HTTP://.