How AWS is organised

Before clicking anything, it helps to know how AWS arranges its world.

Regions and Availability Zones

A Region is a geographic area such as eu-central-1 (Frankfurt) or us-east-1 (North Virginia). Each Region contains several Availability Zones (AZs), separate data centre groups with independent power and networking, connected by fast links.

Most resources live in one Region. An EC2 instance in Frankfurt does not appear when the console is set to Ireland, which is the most common reason beginners think a resource "disappeared". Always check the Region selector in the top right of the console.

Spreading resources across two or more AZs protects against the failure of one data centre. That is the basis of high availability on AWS.

Global and regional services

Some services are global, such as IAM and Route 53. Most are regional, such as EC2, S3 buckets (the bucket lives in one Region even though its name is globally unique), RDS and Lambda.

Accounts

An AWS account is a container for resources and the boundary for billing and security. Larger organisations use many accounts, grouped with AWS Organizations, to separate production from development. For this course, one account is enough.

The shared responsibility model

AWS is responsible for the security of the cloud: data centres, hardware and the software that runs the services. You are responsible for security in the cloud: who can access your account, how your servers are patched, whether your buckets are public, how your data is encrypted.

Almost every cloud security incident in the news comes from the customer side: leaked keys, overly broad permissions, publicly readable storage. This course spends real time on those topics for exactly that reason.

Ways to work with AWS

• Console: the web interface. Great for learning and exploring.
• CLI: the aws command line tool. Repeatable, scriptable, and it shows exactly what you asked for.
• SDKs and infrastructure as code: for applications and for managing resources at scale.

We use the console and the CLI side by side throughout the course.