5 AWS Concepts Every Developer Should Know Before Touching EC2

Source: Dev.to

Introduction

You don’t need to be a cloud architect — but knowing these five concepts will save you hours of pain. If you’re jumping into AWS for the first time, it can feel overwhelming: hundreds of services, confusing pricing, and a console that looks like a cockpit. Most of what you need day‑to‑day comes down to five core concepts. Learn these and everything else starts to click.

Virtual Private Cloud (VPC)

A Virtual Private Cloud (VPC) is your own isolated section of AWS. Think of it as renting a floor in a massive building — other tenants are there, but they can’t get into your space. Every resource you create (EC2, RDS, Lambda) lives inside a VPC.

Best practice: Always create a custom VPC instead of using the default one; it gives you full control over your network.

Security Groups

Security Groups control who can talk to your resources and on which ports.

Key rule:

• Only open the ports you actually need. Nothing more.

Example: A web server typically needs ports 80 (HTTP), 443 (HTTPS), and 22 (SSH). Opening everything is the #1 beginner mistake that leads to security breaches.

Elastic Compute Cloud (EC2)

Elastic Compute Cloud (EC2) is a virtual machine running in AWS. You pick the operating system, the instance size, and the storage, and AWS runs it for you 24/7.

Quick tip on instance sizes:

Simple Storage Service (S3)

Simple Storage Service (S3) is object storage — essentially an infinitely large hard drive in the cloud. Common uses include:

• Storing images, videos, and documents
• Hosting static websites
• Saving application backups
• Storing Terraform state files

S3 is inexpensive, offers 99.999999999% durability, and integrates with almost every other AWS service.

Identity and Access Management (IAM)

Identity and Access Management (IAM) is how you control permissions in AWS.

Golden rule of IAM:

• Give every user and service the minimum permissions they need — nothing extra.

Never use your root account for daily work. Create an IAM user with only the permissions you need. This habit prevents the majority of AWS security incidents.

How the Pieces Fit Together

Your App
   ↓
EC2 (runs your code)
   ↓
VPC + Security Groups (keeps it secure)
   ↓
S3 (stores your files)
   ↓
IAM (controls who can access what)

Mastering these five concepts gives you a solid foundation for everything else AWS throws at you — EKS, RDS, Lambda, and more.