What is SSL?
SSL stands for Secure Sockets Layer
SSL is encryption between the user and the website, so any data the user enters for example address details via a contact form or entering credit card details, cannot be intercepted and used by anyone if there is an SSL in place.
You can tell if a website has one by having a look at the website address. For example if you go to Polyspiral.com you'll see a lock top left and the address will be https:// rather than http://.
Google are beginning to favour websites with SSL encryption and there will soon be warnings like this one:
So if you don’t have an SSL it’s worth getting your website developer to install one. We provide free SSL Certificates with every website as standard, see our website hosting for details.