Cloud Computing: Master Study Notes
Core Concepts • Service Models • Deployment • Security • MCQs • October 23, 2026
1. What Is Cloud Computing?
Cloud computing delivers computing resources—such as servers, storage, databases, networking, and software—over a
network on demand. Organizations can use a provider's services and scale resources as needs change instead of managing all
physical infrastructure themselves.
Key characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.
2. Service Models
IaaS (Infrastructure as a Service): Virtualized compute, storage, and networking. Customers typically manage the operating
system and applications.
PaaS (Platform as a Service): A managed environment for developing and deploying applications.
SaaS (Software as a Service): A complete application accessed over a network, with most platform management handled by
the provider.
Memory aid: IaaS = infrastructure; PaaS = development platform; SaaS = ready-to-use software.
3. Deployment Models
Public cloud: Provider-operated services shared by multiple customers.
Private cloud: Environment dedicated to one organization.
Hybrid cloud: Integrates private infrastructure with public-cloud services.
Community cloud: Shared by organizations with common requirements.
4. Benefits and Limitations
Benefits: flexible scaling, rapid provisioning, managed services, remote access, backup options, and usage-based pricing.
Limitations: network dependence, outages, vendor lock-in, unexpected bills, compliance obligations, and security
misconfiguration.
5. Core Technologies
Virtualization: Multiple virtual systems share physical hardware.
Containers: Package applications with their dependencies.
Orchestration: Automates deployment and management of containers or services.
Serverless: Runs code without requiring customers to manage servers directly; servers still exist behind the service.
Load balancing: Distributes requests across resources.
Auto-scaling: Adjusts capacity to demand.
6. Storage and Databases
Object storage: Suitable for files, media, and backups. Block storage: Provides volumes for virtual machines and
applications. File storage: Provides shared directory-style access. Managed databases reduce maintenance, but data design,
backups, and access control still matter.
7. Security and Shared Responsibility
The provider secures aspects of the underlying cloud infrastructure. Customers remain responsible for their data, identities,
permissions, application settings, and other controls depending on the service model.
Best practices: multi-factor authentication, least-privilege access, encryption, secure backups, logging, monitoring, patching,
network controls, and tested incident-response plans. Never publish passwords or API keys in public repositories.
8. Reliability and Disaster Recovery
High availability reduces service downtime. Fault tolerance allows a system to continue through certain failures. Backups
preserve recoverable copies of data. Disaster recovery defines how systems and data are restored after a major disruption.
Recovery procedures should be tested.
9. Cost Management
Core Concepts • Service Models • Deployment • Security • MCQs • October 23, 2026
1. What Is Cloud Computing?
Cloud computing delivers computing resources—such as servers, storage, databases, networking, and software—over a
network on demand. Organizations can use a provider's services and scale resources as needs change instead of managing all
physical infrastructure themselves.
Key characteristics: on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.
2. Service Models
IaaS (Infrastructure as a Service): Virtualized compute, storage, and networking. Customers typically manage the operating
system and applications.
PaaS (Platform as a Service): A managed environment for developing and deploying applications.
SaaS (Software as a Service): A complete application accessed over a network, with most platform management handled by
the provider.
Memory aid: IaaS = infrastructure; PaaS = development platform; SaaS = ready-to-use software.
3. Deployment Models
Public cloud: Provider-operated services shared by multiple customers.
Private cloud: Environment dedicated to one organization.
Hybrid cloud: Integrates private infrastructure with public-cloud services.
Community cloud: Shared by organizations with common requirements.
4. Benefits and Limitations
Benefits: flexible scaling, rapid provisioning, managed services, remote access, backup options, and usage-based pricing.
Limitations: network dependence, outages, vendor lock-in, unexpected bills, compliance obligations, and security
misconfiguration.
5. Core Technologies
Virtualization: Multiple virtual systems share physical hardware.
Containers: Package applications with their dependencies.
Orchestration: Automates deployment and management of containers or services.
Serverless: Runs code without requiring customers to manage servers directly; servers still exist behind the service.
Load balancing: Distributes requests across resources.
Auto-scaling: Adjusts capacity to demand.
6. Storage and Databases
Object storage: Suitable for files, media, and backups. Block storage: Provides volumes for virtual machines and
applications. File storage: Provides shared directory-style access. Managed databases reduce maintenance, but data design,
backups, and access control still matter.
7. Security and Shared Responsibility
The provider secures aspects of the underlying cloud infrastructure. Customers remain responsible for their data, identities,
permissions, application settings, and other controls depending on the service model.
Best practices: multi-factor authentication, least-privilege access, encryption, secure backups, logging, monitoring, patching,
network controls, and tested incident-response plans. Never publish passwords or API keys in public repositories.
8. Reliability and Disaster Recovery
High availability reduces service downtime. Fault tolerance allows a system to continue through certain failures. Backups
preserve recoverable copies of data. Disaster recovery defines how systems and data are restored after a major disruption.
Recovery procedures should be tested.
9. Cost Management
