📚 IT & AWS Basics Summary

1. Basic IT Terms

  • Network: A connection of cables, routers, and servers.
  • Router: A device that decides where to send data packets over the internet.
  • Switch: Sends a packet to the correct server or client within the network.

2. Five Key Characteristics of Cloud Computing

  1. On-demand self service – Instantly get resources without human help.
  2. Broad network access – Access resources from different devices via the internet.
  3. Multi-tenancy & Resource pooling – Multiple users share the same resources securely.
  4. Rapid elasticity & Scalability – Quickly scale up or down when needed.
  5. Measured service – Pay only for the resources you use.

3. Six Advantages of Cloud Computing

  • No need to buy hardware; pay only for what you use.
  • Lower costs through large-scale efficiency.
  • Scale based on real usage.
  • Faster development and deployment.
  • No need to run and maintain your own data center.
  • Go global within minutes.

4. Problems Solved by the Cloud

  • Flexibility: Change resource types anytime.
  • Cost-effectiveness: Pay-as-you-go model.
  • Scalability: Handle higher loads by adding or upgrading hardware.
  • Elasticity: Scale in and out when needed.
  • High availability & Fault tolerance: Spread across multiple data centers.
  • Agility: Develop and launch quickly.

5. Cloud Service Types – Examples

  • IaaS: AWS EC2, GCP, Azure.
  • PaaS: AWS Elastic Beanstalk, Heroku.
  • SaaS: Gmail, Dropbox, Zoom.

6. AWS Pricing Basics

  • Compute: Pay for the time you use computing resources.
  • Storage: Pay for the data stored in the cloud.
  • Data Transfer: Pay for data going out of the cloud (incoming is free).

7. AWS Regions

  • A region is a cluster of data centers around the world.
  • Choosing a region depends on:
    • Legal & compliance requirements.
    • Distance to customers (lower latency).
    • Services available in the region.
    • Pricing differences.

8. AWS Availability Zones (AZ)

  • Each region has 3–6 independent data centers.
  • Redundant power, networking, and connectivity.
  • Separated to avoid disasters and connected with high-speed, low-latency links.

9. AWS Edge Locations (Points of Presence)

  • 400+ locations in over 90 cities across 40+ countries.
  • Deliver content to users with lower latency.

10. AWS Service Scope

  • Global services: IAM, Route 53, CloudFront, WAF.
  • Region-specific services: EC2, Elastic Beanstalk, Lambda, Rekognition.