The National Motor Freight Traffic Association (NMFTA) publishes a list of freight class designations, codes, and subclasses for commonly shipped items (https://classit.nmfta.org/). A subscription is required to view this list. You can read more about freight classes at Koho for free on our freight classes pages.
The class determines the cost of the shipping. The lower the class, the lower the cost.
Yes. If your shipment can be stacked, it allows the carrier to fit more freight into their truck.