Salesforce Commerce Cloud is a Salesforce Cloud product made up of multiple products, including B2C Commerce, B2B Commerce, and Order Management.
Salesforce Commerce Cloud solution is made up of multiple products, including B2C Commerce, B2B Commerce, and Order Management.
Historically, B2C Commerce was a product known as Demandware. B2B Commerce was a product known as CloudCraze. Both were acquired by Salesforce and rolled into the Commerce Cloud platform. Order Management is built on Salesforce's core platform, and replaces an order maangement product that they had previously which was acquired from Mainstreet Commerce.
More information can be found on Salesforce's website: https://www.salesforce.com/products/commerce-cloud/overview/