Salesforce Commerce Cloud is an eCommerce platform. It provides an backend admin site which is known as the business manager & also provides storefront where a company sell products on line. I have worked quite extensively with platform since 2015 when it was originally created a by a company Demandware which was bought by Salesforce.

My Trailhead profile for Salesforce Commerce Cloud. Trailhead is a great resource to learn more about SFCC & other Salesforce cloud platforms.