The Cloud Security Alliance Security Guidance for Critical Areas of Focus in Cloud Computing V2.0 is a comprehensive guidance document released in December 2009 by the CSA Security Guidance Working Group. This publication represents the second version of the original document released in April 2009. The guidance document addresses critical security areas that organizations need to consider when adopting and operating cloud computing environments. It provides vendor-neutral recommendations and best practices for securing cloud deployments regardless of the provider or platform used. The document serves as a foundational resource for understanding cloud security concepts and has been updated through multiple versions over the years. Version 4.0 covers 14 security domains that form the basis for the Certificate of Cloud Security Knowledge (CCSK) certification program. The guidance incorporates recommendations from multiple sources including the Cloud Security Alliance's research, ENISA guidelines, and the Cloud Controls Matrix. It is designed to help organizations understand how to keep data secure in cloud environments through comprehensive coverage of security domains and control frameworks. This resource is available as a free download from the Cloud Security Alliance website and is part of their broader research and education initiatives in cloud security.