SSL stands for Secure Sockets Layer. In French, "guaranteed security holds". It is the protocol which allows your visitor to know that he is indeed on a secure site. It is very important for the trust that your visitor places in you (you know the little padlock in the bar of your browser, but also all the S in https: //). It is also the protocol that allows you to protect your SEO kitchen. Your client's credit card number will not be copiable from your website, no one should be able to connect for you, etc. All this has to do with cybersecurity, essential in E-commerce.
All the more important since Google gives a premium to security. So we do it. Especially since it's free and very easy. Get ready, we're going!