Lesson 18: Cloud Computing 101

Cloud computing means delivering 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.

Why the Shift to Cloud?

• Pay-as-you-go: Only pay for the resources you consume.
• Scalability: Instantly scale resources up or down based on demand.
• Global Reach: Deploy applications globally in minutes.
• Reduced Overhead: Companies no longer need to buy and maintain their own physical data centers.

Service Models: IaaS, PaaS, and SaaS

Understanding these models defines the level of control you retain:

1. SaaS (Software as a Service): Fully managed applications (e.g., Gmail, Salesforce). You just use it.
2. PaaS (Platform as a Service): Provides the environment for developing, running, and managing applications (e.g., serverless functions, databases). You manage the code, the provider manages the OS.
3. IaaS (Infrastructure as a Service): Provides fundamental computing resources (virtual machines, storage, networks). You manage the OS and everything above it.

Key Cloud Concepts

• Serverless Computing: Running code without managing any servers (e.g., AWS Lambda).
• Regions and Availability Zones (AZs): Geographical distribution for resilience and speed.

Conclusion: Whether you pursue Development, Data, or Security, you will interact with the cloud. It is the modern operating environment.