Cloud Computing

Intermediate

Cloud computing is the delivery of computing services—including servers, storage, databases, networking, software, analytics, and intelligence—over the internet (the cloud) to offer faster innovation, flexible resources, and economies of scale. Rather than owning and maintaining physical data centers and servers, organizations can rent access to anything from applications to storage from a cloud service provider on a pay-as-you-go basis. This model has fundamentally transformed how businesses and individuals consume technology, shifting capital expenditures into operational expenses and enabling rapid scaling to meet demand.

The cloud computing landscape is dominated by three major service models: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). Each model offers different levels of control, flexibility, and management. Additionally, deployment models such as public cloud, private cloud, hybrid cloud, and multi-cloud strategies allow organizations to tailor their approach based on security requirements, compliance needs, and performance goals. Major providers like Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP) compete fiercely, continuously expanding their service catalogs to encompass machine learning, edge computing, serverless architectures, and more.

The adoption of cloud computing has accelerated dramatically, particularly following the global shift toward remote work and digital-first business strategies. Modern cloud architectures emphasize principles like microservices, containerization, infrastructure as code, and DevOps practices that enable continuous integration and continuous delivery (CI/CD). Understanding cloud computing is now essential for IT professionals, software developers, system architects, and business leaders alike, as it underpins virtually every modern application—from streaming media and e-commerce platforms to scientific research and artificial intelligence workloads.

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A cloud computing model that provides virtualized computing resources over the internet, including virtual machines, storage, and networking. IaaS gives users the most control over their computing environment while eliminating the need to manage physical hardware.

Example

A startup uses Amazon EC2 instances to host its web application, scaling from 2 servers during normal traffic to 20 servers during a product launch, paying only for the compute time actually consumed.

A cloud service model that provides a platform allowing customers to develop, run, and manage applications without dealing with the underlying infrastructure. PaaS abstracts away operating system management, patching, and server provisioning so developers can focus solely on writing code.

Example

A development team deploys a web application on Heroku or Google App Engine, pushing code directly from their repository while the platform handles load balancing, scaling, and runtime environment management automatically.

A cloud delivery model where software applications are hosted by a provider and made available to customers over the internet, typically via a web browser. SaaS eliminates the need for organizations to install, maintain, or update software on individual machines.

Example

A company uses Salesforce for customer relationship management and Google Workspace for email and collaboration, accessing both entirely through web browsers with no local installation required.

A cloud execution model where the cloud provider dynamically manages the allocation and provisioning of servers. Despite its name, servers still exist but developers do not need to think about them. Billing is based on actual resource consumption rather than pre-purchased capacity.

Example

A developer writes an AWS Lambda function that processes uploaded images, resizing and optimizing them. The function runs only when an image is uploaded and costs fractions of a cent per invocation.

A lightweight form of virtualization that packages an application and its dependencies into a standardized unit called a container. Containers share the host operating system kernel, making them more efficient than traditional virtual machines while ensuring consistent behavior across environments.

Example

A team packages its microservices application into Docker containers and orchestrates them using Kubernetes on Google Kubernetes Engine, enabling consistent deployment across development, staging, and production environments.

A computing architecture that combines on-premises infrastructure (private cloud) with public cloud services, allowing data and applications to move between the two environments. This approach provides greater flexibility and more deployment options while meeting regulatory and compliance requirements.

Example

A hospital keeps sensitive patient health records on its private cloud for HIPAA compliance while using AWS for its public-facing appointment scheduling system and data analytics workloads.

The ability of a cloud system to automatically adjust computing resources based on real-time demand. Auto-scaling monitors metrics like CPU usage, memory consumption, or request counts and adds or removes instances to maintain performance and optimize costs.

Example

An e-commerce website automatically scales from 5 to 50 server instances on Black Friday when traffic spikes tenfold, then scales back down to 5 instances the following week when demand normalizes.

The practice of managing and provisioning computing infrastructure through machine-readable configuration files rather than through manual processes or interactive tools. IaC enables version control, repeatability, and automated deployment of entire infrastructure stacks.

Example

A DevOps engineer uses Terraform scripts to define an entire production environment—VPCs, subnets, load balancers, databases, and compute instances—and deploys identical environments across multiple AWS regions with a single command.

An architecture where a single instance of a software application serves multiple customers (tenants). Each tenant's data is isolated and invisible to other tenants, even though they share the same underlying infrastructure and application codebase.

Example

Thousands of different companies use the same Slack installation, each seeing only their own workspaces, channels, and messages, while Slack's infrastructure efficiently shares resources among all tenants.

An approach to building and running applications that fully exploits the cloud computing delivery model, using practices such as microservices, containers, service meshes, immutable infrastructure, and declarative APIs. Cloud-native applications are designed for resilience, scalability, and rapid iteration.

Example

Netflix built its streaming platform as a cloud-native application on AWS, using hundreds of microservices that can be independently deployed, scaled, and updated without affecting the overall system.

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Grade level

Grades 9-12College+Adult / Professional

Learning objectives

•Identify the core service models of cloud computing including IaaS, PaaS, and SaaS and their use cases
•Apply cloud architecture patterns including microservices, serverless, and containerization to design scalable applications
•Analyze cloud security risks and implement identity management, encryption, and compliance controls effectively
•Evaluate cloud migration strategies by assessing cost optimization, performance requirements, and vendor lock-in risks

Recommended Resources

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Books

Cloud Computing: Concepts, Technology & Architecture

by Thomas Erl

Designing Data-Intensive Applications

by Martin Kleppmann

Terraform: Up and Running

by Yevgeniy Brikman

Kubernetes Up and Running

by Brendan Burns, Joe Beda, and Kelsey Hightower

The Phoenix Project

by Gene Kim, Kevin Behr, and George Spafford

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Cloud Computing

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Flashcards

Cheat Sheet

Glossary

Learning Roadmap

Book

Key Concepts

Infrastructure as a Service (IaaS)

Platform as a Service (PaaS)

Software as a Service (SaaS)

Serverless Computing

Containerization

Hybrid Cloud

Auto-Scaling

Infrastructure as Code (IaC)

Multi-Tenancy

Cloud-Native Architecture

Explore your way

Grade level

Learning objectives

Recommended Resources

Books

Cloud Computing: Concepts, Technology & Architecture

Designing Data-Intensive Applications

Terraform: Up and Running

Kubernetes Up and Running

The Phoenix Project

Related Topics

Cybersecurity

Software Engineering

Data Engineering