Cloud Computing Fundamentals and Alibaba Cloud Overview
Core concepts
Alibaba Cloud organizes its catalog around the same IaaS/PaaS/SaaS ladder you see elsewhere, but exam questions lean on its own vocabulary. Know the difference between a Region (a geographic area such as Hangzhou or Frankfurt) and a Zone (an isolated datacenter with independent power and network inside a region). Multi-zone deployment is the standard answer for high availability; multi-region is the answer for disaster recovery and latency reduction. Regions are generally isolated from each other, so resources do not span regions by default.
Understand the shared responsibility model: Alibaba Cloud secures the physical infrastructure and hypervisor; you secure what you put on top (OS patching on ECS, bucket policies, RAM permissions). Know the account hierarchy: an Alibaba Cloud account is the root identity, and Resource Access Management (RAM) users and roles live under it.
Traps
- Questions that say "automatically replicated across regions" are almost always wrong; most managed services replicate within a region across zones.
- Distinguish pay-as-you-go, subscription, and preemptible/spot billing. Spot is cheapest and can be reclaimed; subscription is cheapest for steady long-term load.
- "Free tier" and trial credits are not the same as unlimited usage.
Rule of thumb
If a scenario stresses availability within one country, answer multi-zone in one region. If it stresses surviving a regional outage or serving distant users, answer multi-region plus a global traffic mechanism.