# Cloud Computing Fundamentals

## What is Cloud Computing?

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.

## Service Models

### Infrastructure as a Service (IaaS)
- Provides virtualized computing resources
- Examples: AWS EC2, Google Compute Engine, Azure VMs

### Platform as a Service (PaaS)
- Provides platforms allowing customers to develop, run, and manage applications
- Examples: Heroku, Google App Engine, Azure App Service

### Software as a Service (SaaS)
- Delivers software applications over the internet
- Examples: Google Workspace, Microsoft 365, Salesforce

## Deployment Models

### Public Cloud
- Services offered over the public internet
- Available to anyone who wants to purchase them

### Private Cloud
- Cloud infrastructure operated solely for a single organization
- Can be managed internally or by a third party

### Hybrid Cloud
- Combination of public and private clouds
- Allows data and applications to be shared between them

## Key Benefits

- **Cost Efficiency**: Pay-as-you-go pricing
- **Scalability**: Easy to scale resources up or down
- **Reliability**: Data backup, disaster recovery, and business continuity
- **Performance**: Regular upgrades to the latest technology
- **Security**: Policies, technologies, and controls that strengthen security