On-demand delivery of IT capabilities, including infrastructure and applications, over the Internet on a metered basis
MEMORY HOOK: On-demand + Internet + Metered
WHAT CLOUD PROVIDES (EXAM)
Provides
Servers
Storage
Databases
Networking
Software
Analytics
KEY CHARACTERISTICS OF CLOUD COMPUTING (VERY IMPORTANT)
Characteristic
Explanation
On-demand self-service
Users can provision resources without human interaction
Broad network access
Services available over network via standard platforms
Resource pooling
Provider pools resources for multiple tenants
Rapid elasticity
Resources scale up/down quickly
Measured service
Pay-per-use billing model
Automated management
Reduced manual administration
MEMORY HOOK: On-demand, pooled, elastic, measured
LIMITATIONS OF CLOUD COMPUTING (EXAM)
Limitation
Limited control and flexibility
Security, privacy, and compliance issues
Dependency on Internet
Vendor lock-in
Technical vulnerabilities
Migration difficulties
EXAM TRAP: Cloud does NOT automatically guarantee security.
TYPES OF CLOUD COMPUTING SERVICES (CRITICAL)
INFRASTRUCTURE-AS-A-SERVICE (IaaS)
Aspect
Details
What it provides
Virtual machines, storage, networks
User controls
OS, applications, data
Provider controls
Hardware, virtualization
Examples
AWS EC2, Microsoft Azure, Google Compute Engine
ADVANTAGES
Advantage
Dynamic scaling
Guaranteed uptime
Elastic load balancing
Global accessibility
DISADVANTAGES
Disadvantage
Software security risks
Performance dependency
MEMORY HOOK: IaaS = rent hardware
PLATFORM-AS-A-SERVICE (PaaS)
Aspect
Details
What it provides
Application development platform
User controls
Application code
Provider controls
OS, runtime, middleware
Examples
Google App Engine, Azure App Service
ADVANTAGES
Advantage
Simplified deployment
Built-in scalability
Pay-per-use
DISADVANTAGES
Disadvantage
Vendor lock-in
Data privacy issues
MEMORY HOOK: PaaS = build apps
SOFTWARE-AS-A-SERVICE (SaaS)
Aspect
Details
What it provides
Ready-to-use applications
Access
Browser-based
Examples
Gmail, Salesforce, Microsoft 365
ADVANTAGES
Advantage
Low cost
Easy administration
Global access
DISADVANTAGES
Disadvantage
Internet dependency
Switching vendors difficult
MEMORY HOOK: SaaS = use software
IDENTITY-AS-A-SERVICE (IDaaS)
Aspect
Details
Purpose
Authentication and identity management
Functions
MFA, SSO, IAM
Examples
Azure AD, Okta
DISADVANTAGES
Disadvantage
Single point of failure
Account hijacking risk
MEMORY HOOK: IDaaS = cloud login
SECURITY-AS-A-SERVICE (SECaaS)
Aspect
Details
Purpose
Cloud-based security services
Services
IDS, IPS, DLP, SIEM
Examples
Trend Micro, IBM Security
MEMORY HOOK: SECaaS = outsource security
CONTAINER-AS-A-SERVICE (CaaS)
Aspect
Details
Purpose
Manage containers
Technology
Docker, Kubernetes
Examples
AWS EKS, Google GKE
MEMORY HOOK: CaaS = containers
FUNCTION-AS-A-SERVICE (FaaS)
Aspect
Details
Purpose
Run code without servers
Execution
Event-driven
Examples
AWS Lambda, Azure Functions
MEMORY HOOK: FaaS = code only
ANYTHING-AS-A-SERVICE (XaaS)
Aspect
Details
Meaning
Any IT service delivered via cloud
Includes
SaaS, PaaS, MaaS, DRaaS
MEMORY HOOK: XaaS = everything
SHARED RESPONSIBILITY MODEL (EXAM FAVORITE)
Layer
On-Prem
IaaS
PaaS
SaaS
Applications
User
User
User
Provider
Data
User
User
User
Provider
OS
User
User
Provider
Provider
Virtualization
User
Provider
Provider
Provider
Hardware
User
Provider
Provider
Provider
EXAM TRAP: Security is NOT fully provider’s responsibility.
MEMORY HOOK: More service = less control
CLOUD DEPLOYMENT MODELS (CRITICAL)
PUBLIC CLOUD
Aspect
Details
Ownership
Third-party provider
Access
Internet
Examples
AWS, Azure
DISADVANTAGES
Disadvantage
Security not guaranteed
Limited control
PRIVATE CLOUD
Aspect
Details
Ownership
Single organization
Security
High
Cost
High
COMMUNITY CLOUD
Aspect
Details
Shared by
Multiple organizations
Use case
Regulatory needs
HYBRID CLOUD
Aspect
Details
Combination
Public + Private
Benefit
Flexibility
MULTI-CLOUD
Aspect
Details
Uses
Multiple providers
Benefit
Avoid vendor lock-in
MEMORY HOOK: Hybrid = mix, Multi = many
OBJECTIVE 01 — EXAM MEMORY BLOCK
Cloud computing delivers on-demand IT services over the Internet using a pay-per-use model. Service models define responsibility. Deployment models define ownership. Shared responsibility is always tested.