Explore the concept of cloud computing, including types of cloud services (SaaS, PaaS, IaaS), deployment models (public, private, hybrid), benefits, challenges, and real-world applications.
Cloud Computing – Structured Study Notes
| Definition | A model for delivering on‑demand computing resources (servers, storage, databases, networking, software, analytics, AI, etc.) over the Internet, with pay‑as‑you-go pricing. |
|---|---|
| Key Characteristics | • On‑demand self‑service • Broad network access (any device, any location) • Resource pooling (multi‑tenant, virtualized) • Rapid elasticity (scale up/down automatically) • Measured service (usage‑based billing) |
| Primary Benefits | • Reduced capital expenditure (CAPEX) • Faster time‑to‑market • Global reach & reliability • Automatic updates & maintenance • Scalability & flexibility |
| Service Model | What It Provides | Typical Use Cases | Example Providers |
|---|---|---|---|
| IaaS – Infrastructure as a Service | Virtualized compute, storage, networking (VMs, block storage, load balancers) | Hosting legacy apps, dev/test environments, big‑data processing | Amazon EC2, Google Compute Engine, Microsoft Azure VMs |
| PaaS – Platform as a Service | Runtime environment, middleware, development tools, database services | Application development, API management, CI/CD pipelines | Google App Engine, Azure App Service, Heroku |
| SaaS – Software as a Service | Fully functional applications delivered over the web | CRM, email, collaboration, ERP | Salesforce, Office 365, Slack |
| FaaS – Function as a Service (Serverless) | Executes individual functions in response to events, no server management | Event‑driven processing, micro‑services, APIs | AWS Lambda, Azure Functions, Google Cloud Functions |
| DaaS – Desktop as a Service | Virtual desktops delivered to end‑users | Remote workstations, secure corporate desktops | Amazon WorkSpaces, Citrix Virtual Apps |
| Model | Description | Typical Scenarios |
|---|---|---|
| Public Cloud | Resources owned & operated by a third‑party provider, shared among many customers | Start‑ups, variable workloads, global services |
| Private Cloud | Dedicated infrastructure (on‑premises or hosted) for a single organization | Regulated industries, legacy workloads, strict compliance |
| Hybrid Cloud | Combination of public & private clouds with orchestration between them | Bursting to public cloud, disaster recovery, phased migration |
| Multi‑Cloud | Use of two or more public cloud providers simultaneously (not necessarily connected) | Avoid vendor lock‑in, leverage best‑of‑breed services, geographic redundancy |
Virtualization Layer
Compute
Storage