SSL is an acronym for Secure Sockets Layer - a technology that creates a secure connection between the website server and the visitors web browser, allowing private information (such as credit card details) without concerns about tampering, forgery or eavesdropping. You'll see the padlock icon in the address bar quite often when using e-commerce site or online banking, for instance. This is your browsers way of telling you that the connection is secure.
Without SSL, all data sent between websites and your browser is sent in unsecured plain text that if intercepted can be viewed & manipulated by others.
We can of course help secure your site by a SSL certificate if you are handling sensitive data, and will automatically schedule in an annual renewal for the certificate for as long as necessary, meaning it's one less thing for you to worry about. All that will be left is for your website to make use of it by sending visitors to https:// pages instead of http:// whenever you need that data encrypted.