computer hardware

Hardware requires a driver because the hardware in question needs a way to interface with the OS. The driver is a middle man telling the OS and the hardware how to communicate with one another.

Because it doesn't have a license?

Huh?! "Because it doesn't have a license?" not sure what that response is, but everything in the computer is software driven. Hardware is dumb and requires software to give it sense to understand
commands given it and to send its own commands to the CPU so it can do what it is supposed to do. One explanation on tomshardware.com is "A driver is nothing more than software that links your operating system with your hardware. Modern operating systems like Windows 2000 come with a huge set of drivers that support common hardware components. Unfortunately, this set is as old as the operating system itself, typically dating back to its first release. An incredible amount of new hardware is continuously being released, so the operating system cannot possibly detect all hardware components that exist (like motherboard chipsets, controllers, network adapters, sound chips, graphics chips, USB or FireWire controllers etc)..." learn more here

http://www6.tomshardware.com/howto/20010914/driver-01.html

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I strongly recommend that you purchase a book with a title like: "Computing for beginners." Your simplistic questions do not belong in TechRepublic's Technical Q & A section.