Over the last few years, the capabilities and reach of cloud storage services have evolved rapidly, with many organizations expressing interest in storage-as-a-service. With or without the support of traditional storage administrators, cloud storage is infiltrating organizations via developers, business stakeholders, and end users, and I&O teams must look to embrace the use of these services to complement existing storage infrastructure resources. Beyond the potential cost reduction benefits of cloud storage, these services can provide business stakeholders with instantaneous access to resources and let systems of engagements extend the reach of data to customers and partners. This report discusses the four key cloud storage technologies available today and updates Forrester's official definition of cloud storage to reflect its current maturity.