Final answer:
The hard drive is a storage device that stores data permanently even when the computer is turned off. Most hard drives use a technique called giant magnetoresistance to read and write data, which is one of the first large successes of nanotechnology.
Step-by-step explanation:
The hard drive is a storage device, meaning that it stores data permanently even when the computer is turned off.
Most hard drives use a technique called giant magnetoresistance to read and write data. Giant magnetoresistance is the effect of a large change of electrical resistance induced by an applied magnetic field to thin films of alternating ferromagnetic and nonmagnetic layers. This technology is one of the first large successes of nanotechnology.