Cloud Computing Fundamentals
Cloud Computing Fundamentals tests service and deployment models, virtualization versus containers, elasticity, and shared responsibility. Expect scenario questions about choosing the right abstraction and locating operational boundaries.
Service and deployment models
IaaS supplies virtual machines, networks, and storage; you manage the OS and runtime. PaaS supplies a managed runtime or database; you manage code and configuration. SaaS supplies a finished application; you manage users and data. Public cloud is provider-owned, private cloud is dedicated, and hybrid connects both. Regions contain availability zones, which are isolated failure domains.
Virtualization, containers, and responsibility
A hypervisor runs full virtual machines with separate kernels. Containers share the host kernel and isolate processes, making them lighter but not a security boundary equivalent to a VM. Images are built once and run immutably; orchestration schedules and scales them. Under shared responsibility, the provider secures physical facilities and managed infrastructure, while the customer secures identities, configurations, data, and access policies.
Worked example
A small team needs a relational database but has no database administrator. Running a database on an IaaS VM gives full control but leaves patching, backups, and failover to the team. A managed PaaS database shifts those tasks to the provider. The team still chooses the engine, configures network access, manages credentials, and enables backups. The reasoning is to match operational ownership to team capacity, not simply pick the cheapest compute.
Traps
SaaS does not remove responsibility for user access and data handling. Containers are not automatically more secure than VMs. Lift-and-shift moves workloads without exploiting elasticity. Egress traffic and idle resources can dominate cost. Availability zones are not the same as regions.