Information storage in DASDs is a key part of a computer system. The worldwide revenue opportunity for DASD products is more than $50 billion. In order to meet the ever-increasing demand in capacity, performance, and cost-savings, rapid technological advances in magnetic recording have been carried out in laboratories around the world. The recent development for laptop and notepad PCs further demands the need for low power and smaller files. The technology trends in magnetic recording in terms of areal density, volumetric efficiency, and material advances based on published data are reviewed. Optical storage including read-only, write-once, and read/write drives becomes an emerging technology with a removability feature, which may complement magnetic recording DASDs. The recent advances in optical storage media and drives and their comparisons with magnetic recording technology are discussed.