5.2.2 Cloud Computing

Introduction

The textbook explains that Cloud Computing is an IT infrastructure that provides data storage, databases, servers, networking, and application software services over the Internet. In simple words, cloud computing means using computing resources (like storage, servers, and software) over the internet instead of owning and maintaining them locally. You do not need to buy expensive hardware or install software on your own computer . You just use the services provided by cloud service providers.

Definition

Cloud Computing is an IT infrastructure that provides data storage, databases, servers, networking, and application software services over the Internet.

Main Idea

The main idea is that computing resources can be provided as a service over the internet, just like electricity or water . You do not need to own a power plant to get electricity — you just pay for what you use. Similarly, with cloud computing, you do not need to own servers or data centers — you just use cloud services and pay for what you use.

Core Concept

What is Cloud Computing? Cloud computing provides: Data Storage — Store files and data in the cloud1. Databases — Use database services without installing them2. Servers — Use virtual servers for computing3. Networking — Use network services4. Application Software — Use software applications over the internet5. Four Types of Cloud Computing Models The textbook describes four types of cloud computing models: Public Cloud1. Private Cloud2. Community Cloud3. Hybrid Cloud4. Figure 5.5 (Page 157) shows these four types of cloud computing models.

Detailed Explanation

1. Public Cloud Definition: In this cloud computing model, resources are owned and operated by a cloud service provider instead of being installed in-house on

local devices. Key Features: Resources are delivered to businesses and organizations over the Internet Resources include servers, software, and storage Resources are managed and maintained by the cloud service provider Public cloud service providers offer security to customers because of sensitive data stored in the cloud Public cloud provides high-speed connectivity to ensure rapid access to applications and data It provides services to remote users all over the world Services can be: Free Offered on pay-per-usage Offered on subscription charges Examples of Public Cloud: Amazon Web Services (AWS) Microsoft Azure Google Cloud Advantages: Cost-effective (no need to buy hardware) Scalable (can easily increase or decrease resources) Accessible from anywhere Managed by provider (no maintenance needed) Disadvantages:

Less control over data Security concerns (data stored on provider's servers) Dependency on internet connection May not meet specific compliance requirements 2. Private Cloud Definition: This cloud computing model runs on a privately owned IT infrastructure that is used inside a single organization. In other words, cloud computing is dedicated to a single organization. Key Features: Requires huge investment as opposed to public cloud computing model The user organization is responsible for the operation and maintenance of infrastructure (hardware, software, network, etc.) Provides more control over servers and computer network Offers better performance, reliability, and greater flexibility compared to public cloud Advantages: More control over data and resources Better security and privacy Customizable to organization's needs Better performance and reliability Disadvantages: High cost (hardware, software, maintenance) Requires IT staff for management Less scalable than public cloud Limited to organization's resources

3. Community Cloud Definition: Community cloud model is a cloud infrastructure that provides access and services to multiple organizations to share information. Key Features: Suitable for organizations who have common concerns or needs such as: Application Security Policy Mission Compliance It is owned, managed, and operated by: One or more organizations in the community, or A third party It can be on-site or off-site It is cost-effective as it is shared by many organizations It is more secure than public cloud but less secure than private cloud Advantages: Cost-effective (shared among organizations) More secure than public cloud Meets specific community needs Shared resources and expertise Disadvantages:

Less control than private cloud Requires collaboration among organizations Complexity in management Limited to community members 4. Hybrid Cloud Definition: Hybrid cloud is a combination of public and private cloud. Key Features: This cloud computing model uses technology that allows data and applications to be shared between public and private clouds The organizations use public cloud for performing certain tasks They store their sensitive and critical data and applications on the private cloud for fast access and security reasons Advantages: Flexibility (use public cloud for some tasks, private for others) Better security for sensitive data Cost-effective (use public cloud for less sensitive tasks) Scalable (can use public cloud resources when needed) Disadvantages: Complex to manage Requires integration between public and private clouds Security concerns at the boundary Higher cost than public cloud alone Comparison of Cloud Models

Aspect Public Cloud Private Cloud Community Cloud Hybrid Cloud Ownership Cloud provider Single organization Community/Third party Combination Cost Low High Medium Medium-High Security Medium High Medium-High High Control Low High Medium Medium-High Scalability High Low Medium High Examples AWS, Azure, GCP Organization's own cloud Shared by organizations Mix of public and private

Intermediate Level

In a business setting, cloud computing is used for various purposes. Example: An E-commerce Company Public Cloud: Website hosting on AWS Payment processing on Stripe Email service on Google Workspace Private Cloud: Customer database on company's private servers Sensitive financial data on private cloud Hybrid Cloud: Public cloud for website and marketing Private cloud for customer data and transactions

Benefits: Cost savings Scalability during peak seasons Security for sensitive data Flexibility

Important Points

• Cloud Computing = IT infrastructure providing services over the Internet.1.
• Services include: data storage, databases, servers, networking, and application software.2.
• Four types of cloud models:3.
• Public Cloud
• Private Cloud
• Community Cloud
• Hybrid Cloud
• Public Cloud – owned by provider , services over internet, examples: AWS, Azure, GCP .4.
• Private Cloud – dedicated to single organization, high investment, more control.5.
• Community Cloud – shared by multiple organizations with common needs.6.
• Hybrid Cloud – combination of public and private cloud.7.
• Figure 5.5 shows the four types of cloud computing models.8.
• Cloud computing is essential for IoT because it provides storage and processing power .9.

Remember

• Cloud Computing = services over the Internet
• Services: Data storage, databases, servers, networking, application software
• Four types: Public, Private, Community, Hybrid
• Public: AWS, Azure, GCP
• Private: Single organization, high investment
• Community: Shared by multiple organizations
• Hybrid: Combination of public and private
• Figure 5.5 = four types of cloud models
• Examples: AWS, Microsoft Azure, Google Cloud
• Warning: Public cloud is less secure than private cloud

Common Mistakes

• Confusing cloud computing with just storage – Cloud computing includes servers, databases, networking, and software.1.
• Thinking public cloud is always less secure – Public cloud providers have strong security, but less control than private cloud.2.
• Assuming private cloud is always better – Private cloud is expensive and less scalable.3.
• Forgetting about hybrid cloud – Hybrid cloud combines benefits of both.4.
• Not considering cost – Public cloud is cheaper; private cloud is expensive.5.
• Ignoring community cloud – Community cloud is for organizations with common needs.6.
• Confusing cloud models – Each model has different ownership, cost, and security.7.

Quick Revision

Cloud computing is an IT infrastructure that provides data storage, databases, servers, networking, and application software services over the Internet. There are four types of cloud computing models: Public Cloud (owned by provider , services over internet, examples: AWS, Azure, GCP), Private Cloud (dedicated to single organization, high investment, more control), Community Cloud (shared by multiple organizations with common needs), and Hybrid Cloud (combination of public and private). Figure 5.5 in the textbook shows

these four types. Cloud computing is essential for IoT because it provides storage and processing power .

60-Second Revision

Cloud Computing = services over Internet Services: Data storage, databases, servers, networking, application software Four types: Public, Private, Community, Hybrid Public: AWS, Azure, GCP Private: Single organization, high investment Community: Shared by multiple organizations Hybrid: Combination of public and private Figure 5.5 = four types of cloud models Warning: Public cloud is less secure than private cloud Example: Smart home uses cloud to store sensor data