SSL stands for Secure Socket Layer and is a cryptographic protocol that ensures security of transferred data. A proper certificate for a domain may be purchased if there's a need for special security.
You will need such a certificate if you want to accept payments on your website using PayLane's API. Since your customers will enter sensitive data (e.g. card or address information) on your website instead of our Secure Form, you need to provide extra security for the data that will be sent from your website to our payment systems.