If you’re already using Sitecore, then you know that the original commerce in Sitecore wasn’t natively written. Sitecore Commerce 9 changes that.
Sitecore Commerce is now entirely native, eliminating all legacy code. It's written on .net Core, so you can count on a future-proofed solution. The modular design allows you to manage the features you want and exclude those you don’t, simplifying the interface and site administration.