"Why do I need SSL? What even is SSL?" With the rise of ecommerce, it's become increasingly important to keep not only your information secure, but the information of your customers as well. As people running ecommerce shops, you hold on to a lot of sensitive personal information for your customers, and that makes your websites a frequent target for hackers.
When you connect to a webpage, you make a request using the Hypertext Transfer Protocol (HTTP). This is essentially what powers the entire internet. As the number of people using the internet has grown and users put more of their data online, it's become more important to secure that request. Using a normal HTTP request, it's possible for others to intercept your data and steal it. This is generally not a huge deal if you aren't putting private information online, but it is a very big deal if you're trying to check out with a credit card, for instance.
Enter Secure Sockets Layer (SSL) and Transport Security Layer (TLS). Strictly speaking, SSL is actually an older technology that isn't used anymore, and TLS has entirely replaced it, but the terms are used interchangeably. By contacting any one of a number of trusted authorities (SSL.com, GoDaddy, Let's Encrypt, etc.), you can get a certificate that says that your website is, in fact, your website, and not someone trying to pretend that they're you. This allows web browsers to trust your website, and importantly, allows a connection to your website via an encrypted version of HTTP known as HTTPS (HTTP Secure). Now, instead of sensitive data being sent in a way that can be easily intercepted, everything sent between your computer and the server is encrypted and secure. This means that even if someone tries to intercept the request, they can't access the data within it.
SSL is so important to security on the internet that we actually include it on all Version 6 websites. If you go to a website that doesn't have SSL set up nowadays, most browsers will actually tell you that the website is not secure and will try to keep you from visiting the page entirely!