In most storage technologies, the two critical components are the recording head and the recording medium; hence, improvements in storage media go hand in hand with improvements in read/write head technology. Thin films are becoming the dominant medium chosen to meet the burgeoning demand for information storage, and thin-film technology has been transferred to the read/write heads as well. Materials science plays an important role in correlating the structure, properties and processing of thin-film magnetic materials for both applications.