SaaS (Software as a Service): Accessing software through browser; no installation; examples include Google Workspace (Gmail, Docs, Sheets), Microsoft 365 (Word, Excel, Teams), Salesforce. Pay subscription, automatic updates, data stored in cloud.
PaaS (Platform as a Service): Provides development environment and tools; developers can build applications; examples include Heroku, Google App Engine, AWS Elastic Beanstalk. Manages infrastructure, developers focus on code.
IaaS (Infrastructure as a Service): Renting computing resources (servers, storage, networking) over the internet; examples include AWS (Elastic Compute Cloud), Microsoft Azure, Google Cloud. Complete control, most responsibility.
Cloud Service Model Comparison
Model
What's Provided
Examples
Best For
SaaS
Complete applications
Google Workspace, Teams, Slack
End users, everyday work
PaaS
Development platform
Heroku, App Engine
Developers building apps
IaaS
Computing infrastructure
AWS, Azure, Google Cloud
Organizations, full control
Scenario: A startup needs email/collaboration (SaaS: Google Workspace), development tools (PaaS: Heroku), and flexible servers (IaaS: AWS). They use all three layers, scaling and paying only for what they use.
Cloud Deployment Models
Public Cloud
What is it:
Services available to general public
Shared infrastructure (resources shared with other companies)
Managed by cloud provider
Advantages:
Low cost
Scalable
No infrastructure needed
Reliable (provider manages)
Disadvantages:
Less control
Security/privacy concerns
Less customization
Shared resources
Examples:
AWS, Google Cloud, Azure
Dropbox, Google Drive
Private Cloud
What is it:
Dedicated infrastructure for single organization
Only that company uses resources
Can be on-premise or hosted
Advantages:
More secure
Full control
Customizable
Better performance (no sharing)
Disadvantages:
Higher cost
Need technical expertise
Maintenance responsibility
Less scalable
Hybrid Cloud
What is it: Mix of public and private cloud
Flexibility: Choose which apps go where
Sensitive data: In private cloud; non-sensitive in public
Cost balanced: Pay-as-you-go + controlled costs
Complexity: More difficult to manage
Cloud Deployment Model Comparison
Model
Access
Cost
Security
Best For
Public
General public
Low
Standard
Startups, cost-conscious
Private
Single organization
High
High
Finance, healthcare, sensitive
Hybrid
Mix of both
Moderate
Good
Flexible organizations
Scenario: A bank uses private cloud for secure customer financial data (high security). But for non-sensitive apps like email (SaaS), it uses public cloud to save costs. A hybrid approach balances security and budget.
Impact & Implications of Cloud Computing
Cost Considerations
Pay-as-you-go: Only pay for what you use
Low upfront cost: No hardware investment
Scalability: Easily increase/decrease
Predictable costs: Budget friendly
But: High usage can be expensive
Security & Privacy
Data stored remotely: Trust provider
Encryption needed: Protect in transit
Access control: Strong authentication
Compliance: GDPR, DPA requirements
Breaches: Affect all users
Scalability & Flexibility
Scale up: Add resources instantly
Scale down: Remove when not needed
Global access: Anywhere with internet
Automatic updates: Latest features
High availability: Data replicated
Operational Challenges
Internet dependency: Need connection
Provider outages: Your service down too
Data lock-in: Hard to leave provider
Latency: Slight delay possible
Data sovereignty: Where is data stored?
Remote Working Tools & Technologies
VPN (Virtual Private Network)
Purpose: Secure connection to company network from home
How: Encrypts all traffic to company server
Benefits: Appears as if in office network
Access: Company files, printers, systems
Downside: Slower speeds, requires setup
Remote Desktop
Purpose: Control office computer from home
How: Direct connection to office PC
Benefits: Full control of office computer
Examples: Windows Remote Desktop, TeamViewer
Limitations: Office computer must be on
Cloud Storage
What: Files stored online, accessible from anywhere
Examples: OneDrive, Google Drive, Dropbox
Benefits: No USB drives, automatic backup
Sharing: Easy collaboration with team
Sync: Changes on all devices
Collaboration Tools
Video conferencing: Zoom, Teams, Google Meet
Instant messaging: Slack, Microsoft Teams
Real-time editing: Google Docs, Office 365
Project management: Asana, Monday.com, Trello
Benefits: Teamwork despite distance
Online Communities
Types of Online Communities
Social Media: Facebook, Twitter, Instagram – social networking and sharing
Blogs/Vlogs: Written or video content; audience engagement