01. What is AWS - Understanding Cloud Infrastructure

AWS

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Prerequisites

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1. What is AWS

AWS (Amazon Web Services) is a cloud computing platform provided by Amazon.

Instead of buying and maintaining physical servers, AWS allows you to build systems using on-demand infrastructure.

You don’t own servers anymore. You use them when needed.

2. Why AWS Exists

Before cloud computing, building a service required:

• Buying physical servers
• Setting up network infrastructure
• Managing hardware failures
• Predicting traffic in advance

This caused several problems:

• High upfront cost
• Low flexibility
• Difficult scaling
• Maintenance overhead

Traditional Infrastructure (On-Premise)

• Fixed hardware capacity
• Manual scaling
• Hardware management required
• Long provisioning time

Why This Matters for Developers

• Think in systems, not servers
• Design for failure
• Build for scalability
• Automate everything

AWS (Cloud)

• Elastic resources (scale up/down anytime)
• Pay-as-you-go pricing
• Fully managed infrastructure
• Deploy in minutes

Cloud turns infrastructure into software

🧩 Core AWS Services

AWS is composed of many services.
Here are the most essential ones:

Category	Service	Description
Compute	EC2	Virtual servers
Storage	S3	Object storage
Database	RDS	Managed relational DB
Network	VPC	Private network
Scaling	Auto Scaling	Automatic scaling
Load Balance	ELB	Traffic distribution

You don’t build everything from scratch.
You combine services to build systems.