Like the Salesforce Commerce Cloud solution, the answer is complicated.
In 2016, Salesforce acquired Demandware for B2C and rebranded as Salesforce Commerce Cloud In 2018, Salesforce acquired CloudCraze for B2B and rebranded as Salesforce B2B Commerce In 2020 Salesforce released B2B Commerce Lightning Experience, and added B2B2C Commerce for B2B merchants that want to add a direct-to-consumer (DTC) channel To differentiate between B2B offerings, B2B Commerce was rebranded to B2B Commerce on Classic (or Visualforce)
How we compare is simple.
BigCommerce natively offers one composable platform for headless, B2B+B2C, Multi-Storefront, and more.