Cloud Computing Introduction

What is cloud computing?

Cloud computing means renting computing resources (servers, storage, databases, networks, AI models) from a provider over the internet, on demand, and paying for what you use. Instead of buying hardware months in advance, you create a server with an API call in seconds and delete it when you're done.

The big three providers are Amazon Web Services (AWS), Microsoft Azure and Google Cloud. This tutorial uses AWS names first and gives the Azure and Google Cloud equivalents, because the concepts transfer.

Service models

The further down the table, the less you operate and the less you control.

Why companies move to the cloud

• Elasticity: scale up for a sale, down at night.
• Speed: new environments in minutes, through code.
• Managed services: databases, queues and AI services without running servers.
• Global reach: deploy close to users in many regions.
• Cost model: operating expense instead of large capital purchases (but only cheaper if you manage it well).

services = {
    "virtual machines": ("EC2", "Azure Virtual Machines", "Compute Engine"),
    "object storage": ("S3", "Blob Storage", "Cloud Storage"),
    "managed PostgreSQL": ("RDS / Aurora", "Azure Database for PostgreSQL", "Cloud SQL / AlloyDB"),
    "serverless functions": ("Lambda", "Azure Functions", "Cloud Run functions"),
    "Kubernetes": ("EKS", "AKS", "GKE"),
    "message queue": ("SQS", "Service Bus", "Pub/Sub"),
    "identity and access": ("IAM", "Entra ID + Azure RBAC", "Cloud IAM"),
}
print(f"{'':22}{'AWS':16}{'Azure':32}Google Cloud")
for name, (aws, azure, gcp) in services.items():
    print(f"{name:22}{aws:16}{azure:32}{gcp}")

                      AWS             Azure                           Google Cloud
virtual machines      EC2             Azure Virtual Machines          Compute Engine
object storage        S3              Blob Storage                    Cloud Storage
managed PostgreSQL    RDS / Aurora    Azure Database for PostgreSQL   Cloud SQL / AlloyDB
serverless functions  Lambda          Azure Functions                 Cloud Run functions
Kubernetes            EKS             AKS                             GKE
message queue         SQS             Service Bus                     Pub/Sub
identity and access   IAM             Entra ID + Azure RBAC           Cloud IAM