Interface modules are created from a range of components to form a functional working block. They are most commonly used to integrate rf components to form transmitters, receivers or modems.
The Debug Store stocks boards and associated driver software to allow you to start using interface modules quickly. There is no need to design and manufacture a pcb to hold the module before being able to use it.
Just think of the amount of time and expense that can be saved! Be ahead of your competition. Get a functional prototype working quickly. This will allow you to perform user tests before you commit to a final hardware and software design.