SSL stands for Secure Sockets Layer. It's the gold standard for establishing an encrypted link between a browser and a server. The purpose of SSL is to keep any data exchanged between the web server and browser secure. Here’s more on SSL certificates:
Council Post: Why An SSL Certificate Is Important For Your Company Website
With the evolution of the internet, the solutions for better protection of websites increase -- and so does the creativity of cybercriminals. For several years now, organizations like Google have been working toward making the web a safer place by encouraging website owners to use the HTTPS protocol that ensures the data sent from your computer to the site you're browsing is encrypted and securely transmitted.