Cloud Concepts

Foundational cloud principles

What Is Cloud Computing?

On-demand IT resources over the internet with pay-as-you-go pricing.
No servers to buy. No waiting. No tears.

Cloud Service Models

  • IaaS – You manage OS & apps (e.g. EC2)
  • PaaS – You manage code only (e.g. Elastic Beanstalk)
  • SaaS – You manage nothing (e.g. Gmail)

Deployment Models

  • Cloud – All in AWS
  • On-prem – Traditional data center
  • Hybrid – On-prem + cloud
  • Multi-cloud – Multiple providers

Why Cloud? (Exam Favorites)

  • Trade CapEx for OpEx
  • Elasticity – scale up/down automatically
  • High availability
  • Global reach
  • Speed & agility

AWS Global Infrastructure

  • Region – Geographic area (e.g. us-west-2)
  • Availability Zone (AZ) – Isolated data center in a region
  • Edge Location – CDN endpoints (CloudFront)

🧠 High availability = multiple AZs

Shared Responsibility Model (CRITICAL)

AWS: security of the cloud

  • Data centers, hardware, networking, hypervisor

Customer: security in the cloud

  • Data, IAM, OS patches (EC2), app security

Pricing Basics

You pay for:

  • Compute
  • Storage
  • Data transfer OUT

Pricing options:

  • On-Demand – flexible
  • Reserved – cheaper, commitment
  • Spot – cheapest, interruptible
  • F
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