AWS Overview

First PublishedFeb 16, 2026Last UpdatedMar 31, 2026ByAtif Alam

Amazon Web Services (AWS) is the largest cloud platform, offering 200+ services for compute, storage, networking, databases, machine learning, and more. Most modern infrastructure runs on AWS (or a similar cloud), so understanding its core services is essential for DevOps and backend engineers.

Not every workload lives in a public region: on-premises data centers, private connectivity, or hybrid patterns (Kubernetes on AWS plus bare metal elsewhere) are common. The same reliability ideas—IaC (Terraform), observability (Observability), and runbooks—apply; only the network and ownership boundaries change.

Global Infrastructure

AWS is organized into Regions, Availability Zones, and Edge Locations:

                        AWS Global
                            │
          ┌─────────────────┼─────────────────┐
          ▼                 ▼                 ▼
    us-east-1         eu-west-1         ap-southeast-1
    (N. Virginia)     (Ireland)         (Singapore)
      │                 │                 │
   ┌──┼──┐           ┌──┼──┐          ┌──┼──┐
   ▼  ▼  ▼           ▼  ▼  ▼          ▼  ▼  ▼
  AZ-a AZ-b AZ-c   AZ-a AZ-b AZ-c  AZ-a AZ-b AZ-c

Concept	What It Is
Region	A geographic area (e.g. us-east-1 = N. Virginia). Each region is fully independent. Choose the region closest to your users for lower latency.
Availability Zone (AZ)	One or more isolated data centers within a region. AZs have independent power, cooling, and networking. Deploying across multiple AZs provides high availability.
Edge Location	Points of presence for CloudFront (CDN) and Route 53 (DNS). Hundreds worldwide, closer to end users than regions.
Local Zone	AWS infrastructure in a city near a metro area for ultra-low-latency workloads (e.g. gaming, video).

Choosing a Region

Factor	Consideration
Latency	Pick the region closest to your users
Compliance	Data residency laws may require a specific region (e.g. EU data in eu-west-1)
Service availability	Not all services are available in every region
Cost	Pricing varies by region (us-east-1 is often cheapest)

For the full list of regions (codes, names, opt-in status), see the AWS Regions and Availability Zones documentation.

The AWS Console and CLI

AWS Management Console

The web UI at console.aws.amazon.com. Good for exploring services, visual setup, and one-off tasks. Not ideal for repeatable infrastructure (use IaC instead).

AWS CLI

Command-line interface for scripting and automation:

# Install
curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o "awscliv2.zip"
unzip awscliv2.zip && sudo ./aws/install

# Configure credentials
aws configure
# AWS Access Key ID: AKIA...
# AWS Secret Access Key: ...
# Default region name: us-east-1
# Default output format: json

# Example commands
aws s3 ls                           # list S3 buckets
aws ec2 describe-instances          # list EC2 instances
aws iam list-users                  # list IAM users

Credentials are stored in ~/.aws/credentials; config in ~/.aws/config.

AWS SDKs

Programmatic access from code (Python boto3, Node.js aws-sdk, Go aws-sdk-go, Java, etc.):

import boto3

s3 = boto3.client('s3')
response = s3.list_buckets()
for bucket in response['Buckets']:
    print(bucket['Name'])

AWS Free Tier

AWS offers a free tier with three types of free offers:

Type	Duration	Examples
Always free	Indefinite	Lambda (1M requests/month), DynamoDB (25 GB), CloudWatch (10 custom metrics)
12 months free	First 12 months after sign-up	EC2 t2.micro (750 hrs/month), S3 (5 GB), RDS db.t2.micro (750 hrs/month)
Trials	Varies by service	SageMaker (2 months), Inspector (90 days)

Set up a billing alarm in CloudWatch immediately after creating your account — unexpected charges are the most common AWS mistake for newcomers.

Key Terminology

Term	Meaning
ARN	Amazon Resource Name — unique identifier for any AWS resource (e.g. arn:aws:s3:::my-bucket)
IAM	Identity and Access Management — controls who can do what
VPC	Virtual Private Cloud — your isolated network in AWS
EC2	Elastic Compute Cloud — virtual machines
S3	Simple Storage Service — object storage
RDS	Relational Database Service — managed databases
Lambda	Serverless compute — run code without managing servers
CloudFormation	AWS-native Infrastructure as Code (alternative to Terraform)
Tags	Key-value labels on resources for organization, cost tracking, and access control

AWS vs Other Clouds

	AWS	Azure	GCP
Market share	~31% (largest)	~25%	~11%
Strength	Broadest service catalog, most mature	Enterprise/hybrid, Microsoft integration	Data/ML, Kubernetes (GKE)
IaC	CloudFormation, Terraform	ARM/Bicep, Terraform	Deployment Manager, Terraform
Kubernetes	EKS	AKS	GKE
Serverless	Lambda	Azure Functions	Cloud Functions

Topics in This Section

Start with setting up basic access (console + CLI on Mac), then IAM (identity), compute, networking, and storage — the foundational building blocks. Databases, monitoring, CI/CD, and cost management build on top of these.

• Setting up basic access — Steps in the AWS console and on a Mac to get the CLI working.
• IAM — Users, groups, roles, policies, least privilege, and MFA.
• Compute — EC2 instances, Lambda serverless functions, and ECS/EKS containers.
• Networking — VPC, subnets, route tables, gateways, security groups, and NACLs.
• Elastic Load Balancing — ALB, NLB, GWLB, target groups, health checks, troubleshooting, EKS and AWS Load Balancer Controller.
• Route 53 — Hosted zones, routing policies, health checks, Resolver, and DNS diagnosis.
• VPC Connectivity — VPC peering, Transit Gateway, Site-to-Site VPN, and Direct Connect.
• Flow Logs & Network RCA — VPC Flow Logs to CloudWatch or S3, queries for denies and connectivity debugging, and when to add packet capture.
• Storage — S3 object storage, EBS block volumes, and EFS file storage.
• Databases — RDS managed relational databases and DynamoDB NoSQL.
• Monitoring — CloudWatch metrics, logs, alarms, and CloudTrail audit logging.
• CI/CD on AWS — CodePipeline, CodeBuild, and GitHub Actions integration.
• Cost Management — Billing dashboard, Cost Explorer, budgets, and tagging strategy.
• SNS, SQS, EventBridge — Message queues, pub/sub fan-out, and event-driven routing.
• API Gateway — REST and HTTP APIs, Lambda integration, authentication, and throttling.
• CloudFront — CDN edge caching, HTTPS, Origin Access Control, and Lambda@Edge.
• TLS and Certificates — ACM, certificate lifecycle, attaching certs to load balancers and APIs, rotation, and links to Azure and Kubernetes cert patterns.
• Secrets Management — Secrets Manager with rotation and Parameter Store for configuration.
• Security Services — WAF, Shield, GuardDuty, Security Hub, KMS, and Inspector.
• Kinesis / Streaming — Real-time data streaming with Data Streams and Firehose.
• ElastiCache — Managed Redis for caching, sessions, leaderboards, and rate limiting.
• ECR — Container image registry with scanning, lifecycle policies, and cross-account access.
• Well-Architected Framework — The six pillars for building reliable, secure, efficient cloud architectures.