Cloud Concepts and Azure Architecture Review

The Cloud Concepts domain accounts for approximately 25–30% of the AZ-900 exam. Key topics include: the definition and benefits of cloud computing, the shared responsibility model, cloud service models (IaaS/PaaS/SaaS), and cloud deployment models (public/private/hybrid). The exam tests whether you understand which model is appropriate for a given scenario, not just the definitions. Pay particular attention to the six benefits of cloud computing Microsoft lists in the exam objectives.

The shared responsibility model divides security and management responsibilities between Microsoft and the customer. Microsoft always manages: physical data centres, physical network, physical hosts. Customer always manages: data, accounts, and identities. The middle layer shifts depending on service model: for IaaS, customers manage OS, network controls, and applications; for PaaS, Microsoft additionally manages the OS and middleware; for SaaS, Microsoft manages nearly everything except data and account access.