Shipping modules provide the shipping options in your store. Each module supports a single shipping method, like Weight Table Based Shipping, or shipping by a major package delivery company. When you assign a module to the store, and configure the settings for the module, that shipping method is available for your customers to select when they check out.
Select the shipping options you wish to offer to customers in your store then click Update.
In addition to a message at the bottom of the screen confirming that the module has been updated, a tab (link) will appear at the top of the screen for that particular module.