The final version of NIST Special Publication 800-146, Cloud Computing Synopsis and Recommendations is NIST's general guide to cloud computing. It explains cloud systems in plain language and provides recommendations for information technology decision makers ranging from chief information officers, information systems developers, system and network administrators, information system security officer and systems owners. This document presents information on how clouds are deployed, what kind of services are available, economic considerations, technical characteristics such as performance and reliability, typical terms of service, and security issues. It also offers recommendations on how and when cloud computing is an appropriate tool, and surveys open issues for cloud computing.