Why should I define my categories? By classifying your categories with the International Category Classifier, your product catalogue will automatically become compatible with all services using that classifier.
For example: If you want to use Facebook Dynamic Ads or Google Merchant, your categories will need to be classified according to this standard.
What's more, if your products are in classified categories, CloudCart's algorithms will help your customers find more relevant products according to their needs and desires!
We recommend to take a look of this helpful articl for Category section.