The default Magento installation comes with several built-in shipping methods available: Flat Rate, Table Rates, Free Shipping UPS, USPS, FedEx, and DHL. For some merchants, this is more than enough; for others, you are free to build an additional custom shipping extension with support for one or more shipping methods. Be careful about the terminology here. Shipping method resides within shipping extension. A single extension can define one or more shipping methods. In this chapter, we will learn how to create our own shipping method.
There are two, unofficially divided, types of shipping methods: