Secure Socket Layer, is the secure transmission method for data on the Internet. The connection is encrypted by a certificate, the so-called SSL certificate. SSL is worthwhile to protect customer and visitor data in communication. The SSL certificate is recognizable by a lock symbol next to the address URL. This strongly promotes the trust of users towards one's own website. SSL is very often used for webshops, since sensitive data (such as address, credit card data, etc.) is transmitted there.
Meanwhile, the secure connection of a website is also one of the ranking factors in Google when it comes to SEO.