AWS VPC Networking — Public Subnet, Private Subnet and 3-Tier Architecture

Explains how to plan an AWS VPC CIDR block and distinguish public vs. private subnets by routing.

Covers the roles of an Internet Gateway and NAT Gateway in a secure 3-tier architecture.

Shows a setup with public ALB/NAT, private EC2, and isolated RDS subnets across two availability zones.

Demonstrates how to automate the full network layout in Terraform for secure, highly available AWS applications.