The Occupational Information Network (O*NET) has recently been developed as a replacement for the Dictionary of Occupational Titles. As a comprehensive system designed to describe occupations, the O*NET incorporates the last 60 years of knowledge about the nature of jobs and work. This article summarizes its development and validation by first discussing how the O*NET used multiple descriptors to provide “multiple windows” on the world of work, utilized cross-job descriptors to provide a common language to describe different jobs, and used a hierarchical taxonomic approach to occupational descriptors. Second, we provide an overview of the O*NET's Content Model of descriptor domains (i.e., worker characteristics, worker requirements, occupational requirements, experience requirements, occupation characteristics, and occupation-specific requirements) and their potential uses. Third, we discuss some of the technical issues surrounding the O*NET Finally, we discuss some of the implications for research and theory, as well as some limitations of the O*NET system.