Secure websites are marked with an SSL Certificate (Secure Sockets Layer), which authenticates the identity of a website. You’ve seen this on any website whose URL begins https://
Just click the lock icon (on Chrome in this example) and you’ll see further information about the verification of this address. The idea is to assure users that you are who you say you are, and that any data sent through the website will be encrypted.
Having an SSL certificate installed on your site might boost your organic search engine rankings as well. Google likes secure sites too.
Up until very recently, this meant an additional cost, to the tune of anything from $9 to $700 per year, depending on the level of security offered and required going through a process of certificate creation, validation, signing, installation and renewal.
Let’s Encrypt is still in its beta version, but so far it looks promising as a major step toward a more secure internet. You can get started on the Let’s Encrypt website, or check the control panel provided by your website’s hosting provider. Many have begun to offer Let’s Encrypt as a service to their customers.