Final answer:
Optical drives use a laser to read and write data from CDs, whereas historic and some current hard drives use giant magnetoresistance based on nanotechnology advances.
Step-by-step explanation:
Optical drives, which began replacing cassette tapes with compact discs (CDs) in the 1990s, use a laser to read and write data. This technology is based on interpreting variations in reflections of a laser beam from the surface of the CD. Unlike optical drives, some computer hard drives and other magnetic storage devices like audio and video tapes or the magnetic stripes on credit cards, historically relied on the principle of induction for reading data. However, today's hard drives typically employ giant magnetoresistance for data readout, a technique developed from the advancements in nanotechnology, which involves large changes in electrical resistance due to weak changes in a magnetic field within iron and chromium thin films.