In Weight Table Based Shipping you create a set of ranges based on the weight of the customer's total order. Each weight range can have a different shipping charge. For example:
Range 1: 0 - 5 pounds, charge $4.00 to ship the order.
Range 2: 6 - 10 pounds, charge $6.00 to ship the order.
Range 3: 11 - 15 pounds, charge $8.00 to ship the order.
Appendix 3: Comparing Weight Based Shipping Modules
Weight Units, to set the unit of weight used in your store.