Cloud Computing Basics Cheat Sheet

Table 1: Service Models

Service models answer a single question: how much of the stack does the provider manage versus you? The classic trio — IaaS, PaaS, SaaS — runs from renting raw virtual machines to consuming finished applications in a browser, with each step handing off more of the underlying layers. The newer "as-a-service" rows extend the same idea to functions, containers, databases, and even AI, so you can outsource exactly the layer that isn't your core problem.

Table 2: Deployment Models

Where the infrastructure lives and who shares it is a separate decision from which service model you pick. Public cloud means shared, provider-owned infrastructure at maximum scale; private cloud is dedicated to one organization for tighter control; and hybrid and multi-cloud blend approaches to balance cost, compliance, and vendor lock-in. The sovereign and community rows reflect the growing pressure to keep data inside specific legal borders.

Table 3: Essential Characteristics (NIST SP 800-145)

These five traits are NIST's official definition of what makes something genuinely "cloud" rather than just hosting — and they show up constantly on certification exams. Together they describe a system you can provision yourself, reach from any device, that pools resources across many tenants, scales elastically with demand, and meters everything so you pay only for what you use.

Table 4: Core Benefits

This is the "why bother" list — the concrete payoffs that drive organizations off their own data centers. The headline is the shift from capital expense to operational expense, but the rest of the table is just as important: scalability and elasticity to match capacity to demand, agility to ship faster, and the global reach, reliability, and security you'd struggle to build alone. A handy distinction to hold onto is scalability (the ability to grow) versus elasticity (growing and shrinking automatically).

Table 5: Global Infrastructure

Cloud providers organize their physical footprint into a nested geography that you'll deploy into deliberately. Regions are broad geographic areas, availability zones are the isolated data centers inside them that let you survive a single failure, and edge and local zones push compute closer to users for lower latency. Data sovereignty is the legal overlay — the rules dictating which region your data is even allowed to sit in.

Table 6: Computing Resources

These are the actual ways you run code in the cloud, arranged loosely from heaviest to lightest. Virtual machines give you a full OS to control, containers package just your app and its dependencies for faster, denser deployment, and serverless functions strip it down to running code on a trigger with no server to manage. The specialty rows — bare metal, GPU, and spot instances — handle performance-critical, accelerated, or cost-sensitive interruptible workloads.

Table 7: Storage Services

Cloud storage isn't one thing — the type you choose depends on how your data is accessed. Object storage holds unstructured files like media and backups at near-infinite scale, block storage gives VMs fast low-latency volumes for databases, and file storage offers shared network filesystems multiple machines can mount at once. Archive storage trades retrieval speed for the lowest cost, while ephemeral storage is fast but vanishes when the instance stops.

Table 8: Networking Concepts

The VPC is the foundation of cloud networking — your own isolated, software-defined network where you control IP ranges, subnets, and routing. The rest of the table builds outward from there: subnets segment it into public and private zones, load balancers and CDNs distribute traffic, and gateways and connectivity options (VPN, Direct Connect, Transit Gateway, Private Link) govern how traffic flows in, out, and between networks securely.

Table 9: Database Services

There's no universal database, so the cloud offers a managed engine for every data shape. Relational databases handle structured, transactional data with ACID guarantees; NoSQL trades that rigidity for flexible schemas and horizontal scale; and in-memory stores deliver microsecond latency for caching. The specialized rows — data warehouses, time-series, graph, and lakehouse — exist because analytics, sensor streams, relationship data, and mixed structured/unstructured workloads each query very differently.

Table 10: Pricing Models

How you pay for the same resource can swing the bill dramatically. On-demand is the flexible default with zero commitment, while reserved instances and savings plans trade a one-to-three-year commitment for discounts of up to 72%. Spot pricing offers the deepest cuts on spare capacity that can be reclaimed at any moment, and the free tier and data transfer rows are the two that catch newcomers out — one for what's free, the other for the egress charges that quietly add up.

Table 11: Security and Compliance

Security in the cloud starts with the shared responsibility model — understanding the line between what the provider secures and what stays on you is the single most important concept here. The remaining rows are the controls you own on your side of that line: IAM for who can access what, encryption at rest and in transit for protecting data, MFA and zero trust for verifying identity, and security groups, KMS, and WAF for guarding traffic, keys, and applications.

Table 12: Migration Strategies (The 7 Rs)

When moving existing workloads to the cloud, the "7 Rs" are the standard menu of approaches, ranging from minimal change to total reinvention. Rehosting is the fast lift-and-shift that changes nothing, replatforming makes small cloud optimizations along the way, and refactoring fully re-architects for cloud-native benefits. The rest cover the choices to repurchase a SaaS alternative, relocate at the hypervisor level, retire what's no longer needed, or simply retain it on-premises for now.

Table 13: Management and Monitoring

Once workloads are live, these practices keep them healthy, affordable, and under control. Infrastructure as code makes deployments repeatable and auditable, monitoring and observability tell you what's actually happening, and auto scaling adjusts capacity to demand. Rounding it out are the disciplines that keep an estate sane at scale — backup and DR for continuity, FinOps for spend, tagging for organization, landing zones for governance, and SLAs for the uptime you're promised.

Table 14: Development and DevOps

These are the building blocks of modern cloud-native applications and the pipelines that ship them. CI/CD automates build-test-deploy, container orchestration manages fleets of containers, and API gateways expose and protect your services. Message queues and event streaming decouple components for resilience, while artifact registries, secrets management, and service mesh handle storing builds, guarding credentials, and securing service-to-service traffic.

Table 15: Well-Architected Framework Pillars

These six pillars are the lens cloud providers use to evaluate whether a workload is built well, and they make a useful checklist for any architecture review. Each one names a tension worth balancing — operational excellence and reliability for running smoothly and recovering from failure, security for protecting it, performance efficiency and cost optimization for doing more with less, and sustainability for minimizing environmental impact.