Cloud Computing II - SSS 2 Note

CLOUD COMPUTING II

Subject: Digital Technologies
Class: SSS 2
Term: Third Term
Week: 3
Topic: Cloud Computing II
Duration: 80 Minutes (Double Period)

Learning Objectives

By the end of the lesson, students should be able to:

1. Explain Software as a Service (SaaS).
2. Explain Platform as a Service (PaaS).
3. Explain Infrastructure as a Service (IaaS).
4. Distinguish between SaaS, PaaS and IaaS.
5. Identify examples of cloud-based services under the three service models.
6. State common uses of SaaS, PaaS and IaaS.

1. Introduction

In the previous study of cloud computing, we learned that cloud computing allows people and organisations to access computing resources and services through the internet. Instead of keeping everything on a personal computer, users can access applications, storage, computing power and other resources from cloud providers.

Cloud services are provided in different ways. Three important cloud service models are Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS).

These models provide different levels of control and responsibility to the user.

2. Meaning of Cloud Service Models

Cloud service models describe the different ways cloud providers deliver computing resources and services to users over the internet.

The three major cloud service models are:

• Software as a Service (SaaS)
• Platform as a Service (PaaS)
• Infrastructure as a Service (IaaS)

They can be understood by considering how much of the technology is managed by the cloud provider and how much is managed by the user.

3. Software as a Service (SaaS)

Software as a Service (SaaS) is a cloud service model in which a provider makes software applications available to users over the internet.

With SaaS, users normally access the software through a web browser or application without having to install and manage the underlying infrastructure themselves.

Examples of SaaS

• Google Docs
• Google Sheets
• Microsoft 365 online applications
• Canva
• Online email services
• Online collaboration applications

Uses of SaaS

SaaS can be used for:

• Creating and editing documents.
• Preparing spreadsheets.
• Sending and receiving email.
• Creating graphics and presentations.
• Collaborating on school or workplace projects.
• Managing business activities.

Simple example: When a student uses Google Docs through a browser to create a document without installing and managing the software infrastructure behind the service, the student is using a SaaS application.

4. Platform as a Service (PaaS)

Platform as a Service (PaaS) is a cloud service model that provides a platform and development environment that programmers can use to build, test and deploy applications.

PaaS is particularly useful to software developers because the cloud provider manages much of the underlying infrastructure. The developer can concentrate more on creating the application.

Examples of PaaS

Examples include cloud platforms such as:

• Google App Engine
• Microsoft Azure App Service
• Heroku
• Red Hat OpenShift

Uses of PaaS

• Developing software applications.
• Testing applications.
• Deploying web applications.
• Supporting development teams.
• Managing application development environments.

Simple example: A programmer who wants to create and deploy a web application can use a PaaS platform instead of setting up all the required servers and development infrastructure manually.

5. Infrastructure as a Service (IaaS)

Infrastructure as a Service (IaaS) is a cloud service model that provides computing infrastructure such as virtual machines, storage and networking resources over the internet.

Instead of buying and maintaining physical servers, organisations can rent computing infrastructure from a cloud provider and configure it according to their needs.

Examples of IaaS

• Amazon EC2
• Microsoft Azure Virtual Machines
• Google Compute Engine
• DigitalOcean Droplets

Uses of IaaS

• Running websites and applications.
• Providing virtual computers.
• Storing and processing large amounts of data.
• Setting up network resources.
• Supporting business computing systems.
• Testing software in virtual environments.

6. Comparing SaaS, PaaS and IaaS

Service Model	Meaning	Main Users	What It Provides
SaaS	Software as a Service	General users, students, businesses	Ready-to-use software applications
PaaS	Platform as a Service	Developers and programmers	Development platforms and environments
IaaS	Infrastructure as a Service	IT professionals, organisations and developers	Virtual machines, storage, networking and other infrastructure

7. Simple Way to Remember the Three Models

The three service models can be remembered using the following idea:

Model	Think of It As
SaaS	Using a finished application.
PaaS	Using a ready development platform to build applications.
IaaS	Renting the computing infrastructure needed to run systems.

Easy memory aid: SaaS gives you the software, PaaS gives you the platform for development, while IaaS gives you the infrastructure.

8. Differences Between SaaS, PaaS and IaaS

The major difference is the level of control and responsibility given to the user.

• SaaS: The provider manages almost everything and the user mainly uses the application.
• PaaS: The provider manages the underlying infrastructure while the developer focuses on building applications.
• IaaS: The provider supplies infrastructure while the user has greater control over the computing environment.

Feature	SaaS	PaaS	IaaS
Ready-to-use software	Yes	No	No
Application development	Limited	Yes	Yes
Infrastructure control	Very low	Limited	Greater
Main purpose	Use applications	Build and deploy applications	Provide computing infrastructure

9. Advantages of Cloud Service Models

Cloud service models provide several benefits:

• They can reduce the need to purchase physical infrastructure.
• They allow users to access services through the internet.
• They can support collaboration between users in different locations.
• They can make it easier to scale computing resources when needed.
• They can provide access to modern computing tools and services.
• They can reduce some maintenance responsibilities for users.

10. Responsible Use of Cloud Services

Cloud services are useful, but users should use them responsibly.

• Use strong and unique passwords.
• Protect account login information.
• Do not share passwords with other people.
• Use trusted cloud services.
• Be careful when sharing personal or confidential information.
• Respect copyright when uploading or sharing files.
• Log out of shared computers when finished.
• Use appropriate privacy and security settings.

Safety warning: Students should never upload passwords, banking information or other sensitive personal information to an unfamiliar cloud service. Always check the service and account settings before sharing information.

11. Practical Classroom Activity

Activity: Identify and classify cloud services.

1. List five cloud services that you or people around you have used.
2. State what each service is used for.
3. Classify each service as SaaS, PaaS or IaaS where appropriate.
4. Explain why you placed each service in that category.
5. Discuss which cloud service model would be most useful to a student, a software developer and a large organisation.

12. Summary

Cloud computing provides different types of services through the internet. The three major cloud service models are Software as a Service (SaaS), Platform as a Service (PaaS) and Infrastructure as a Service (IaaS). SaaS provides ready-to-use applications, PaaS provides platforms for developing and deploying applications, while IaaS provides computing infrastructure such as virtual machines, storage and networking resources. Understanding these models helps users select appropriate cloud services for different needs.

13. Evaluation Questions

1. What is a cloud service model?
2. What does SaaS mean?
3. Explain Platform as a Service.
4. What is Infrastructure as a Service?
5. State two examples of SaaS.
6. Mention two examples of PaaS.
7. Mention two examples of IaaS.
8. State two differences between SaaS and PaaS.
9. State two differences between PaaS and IaaS.
10. Which cloud service model provides ready-to-use software?

14. Assignment

Prepare a table containing the following information about SaaS, PaaS and IaaS:

1. Full meaning of each term.
2. Definition of each service model.
3. Two examples of each model.
4. Two uses of each model.
5. One major difference between the three models.

15. Interactive Revision Quiz

Choose the correct answer for each question, then click Mark Quiz to see your score.

1. What does SaaS stand for?

A. Software as a Service B. Storage as a System C. Software and Security System D. Server as a Software

2. Which cloud service model provides ready-to-use software?

A. IaaS B. PaaS C. SaaS D. LAN

3. What does PaaS provide mainly?

A. A physical keyboard B. A platform for developing and deploying applications C. A replacement for the internet D. Only email accounts

4. What does IaaS stand for?

A. Internet as a Service B. Information as a System C. Infrastructure as a Service D. Internet Application and Software

5. Which of the following is an example of SaaS?

A. Google Docs B. A physical server C. A network cable D. A computer mouse

6. Which cloud model is especially useful for software developers?

A. PaaS B. Printer as a Service C. Keyboard as a Service D. Paper as a Service

7. Which of the following is commonly associated with IaaS?

A. Virtual machines B. Printed textbooks C. Classroom desks D. Physical notebooks

8. Which model generally gives users the greatest control over the computing environment?

A. SaaS B. PaaS C. IaaS D. None

9. Which statement is correct?

A. SaaS provides only physical computers B. PaaS provides a development platform C. IaaS is only used for email D. None of the above

10. Why should users protect their cloud-service passwords?

A. To make the computer heavier B. To protect their accounts and information C. To stop the internet from working D. To delete cloud services