Module 1 cheat sheet: Cloud Foundations
The cloud lets you rent IT over the internet; AWS runs it from Regions and Availability Zones on virtualised servers.
Key ideas
- Traditional IT = big CapEx (buy) + OpEx (run). Cloud turns CapEx into pay-as-you-go OpEx. Day 1 →
- IaaS (EC2) · PaaS (Elastic Beanstalk) · SaaS (Gmail). Day 2 →
- Public (shared) · private (one organisation) · hybrid (both, via VPN/Direct Connect). Day 2 →
- Region ⊃ Availability Zones ⊃ data centres; edge locations cache content. Day 3 →
- Virtualization: one host, many VMs; EC2 runs on the Nitro hypervisor. Day 4 →
Who manages what
| Layer | IaaS | PaaS | SaaS |
|---|---|---|---|
| Hardware | AWS | AWS | AWS |
| OS & runtime | you | AWS | AWS |
| App & data | you | you | AWS (data: you) |
Choose a Region by
- compliance / data residency
- latency to users (India → Mumbai ap-south-1, Hyderabad ap-south-2)
- service availability
- price
Hypervisors
| Type | Runs on | Examples |
|---|---|---|
| Type 1 (bare-metal) | hardware | ESXi, Hyper-V, AWS Nitro |
| Type 2 (hosted) | a host OS | VirtualBox, VMware Workstation |
New account checklist
- MFA on the root user
- budget alert (e.g. $5)
- IAM Identity Center / IAM user for daily work
- never create root access keys
- stop or terminate everything after practice
Common mistakes
- Calling “11 nines” AWS availability: it is S3 durability.
- Running everything in one AZ.
- Using the root user every day.
- Forgetting to terminate practice resources.
Created by Ajeetkumar · EasyLearnSpace