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Cloud Computing Overview

Jul 6, 2025

Overview

This lecture covers the fundamentals of cloud computing, its advantages, various cloud deployment models, and the differences between service models like IaaS, PaaS, and SaaS.

Cloud Computing Fundamentals

  • Cloud computing allows hosting applications and services outside of local data centers.
  • Provides access to large-scale computing resources (CPU, storage, network) on demand.
  • Applications can be deployed or removed globally in moments, offering flexibility and scalability.

Advantages of Cloud Computing

  • Reduces time and effort needed for deploying applications compared to traditional physical data centers.
  • Enables geographic flexibility by hosting services closer to end-users.
  • Offers cost efficiency by paying only for resources used and avoiding large upfront investments.
  • Supports scaling resources up or down based on demand.

Cloud Deployment Models

  • Public Cloud: Services provided by third parties (e.g., Microsoft, Amazon) accessible via the internet.
  • Private Cloud: Hosted internally within a company’s own data center for greater control.
  • Hybrid Cloud: Combines both public and private clouds, used simultaneously for different needs.
  • Community Cloud: Shared cloud infrastructure among organizations with similar requirements to share costs.

Cloud Service Models

  • Infrastructure as a Service (IaaS/HaaS): Rent hardware resources; customer manages OS, applications, and data.
  • Software as a Service (SaaS): Use web-based applications managed entirely by the provider (e.g., Google Mail, Microsoft 365).
  • Platform as a Service (PaaS): Provider manages the platform; customer develops and runs custom applications on it (e.g., Salesforce development platform).

Responsibility Matrix

  • In IaaS, the provider manages hardware and networking; the customer manages OS, apps, and data.
  • In SaaS, the provider manages almost everything except end-user devices and authentication.
  • In PaaS, the provider supplies the platform; the customer develops and controls applications.
  • On-premises solutions require the customer to manage every aspect of the infrastructure.

Key Terms & Definitions

  • Cloud Computing — Delivery of computing resources over the internet.
  • Public Cloud — Third-party cloud services open to all users.
  • Private Cloud — Cloud environment operated solely for one organization.
  • Hybrid Cloud — Combination of public and private clouds.
  • IaaS (Infrastructure as a Service) — Cloud service model renting virtualized hardware.
  • PaaS (Platform as a Service) — Cloud service model providing a platform for application development.
  • SaaS (Software as a Service) — Cloud service model delivering ready-to-use software over the internet.

Action Items / Next Steps

  • Review the differences between IaaS, PaaS, and SaaS for future exams.
  • Compare public, private, and hybrid cloud scenarios in terms of control and responsibility.