Cloud Computing: Modern Digital Skills Study Guide

Overview of Cloud Computing: Definition and Purpose

• Cloud Computing Definition: The delivery of various computing services, including storage, processing, and software, over the internet (referred to as "the cloud") rather than through a user's local device.

• The Cloud: Conceptually defined as a network of servers that work together to deliver these computing services over the internet.

• Purpose of Cloud Computing: To enable users to store, manage, and process data effectively, regardless of their physical location.

Cloud Computing Components

• Clients: These are the end users who seek access to programs, data, and storage anytime and anywhere, provided an internet connection is available.

• Internet Connectivity: The specific method used by clients to connect to the internet, which includes Wi-Fi and various wireless devices.

• Service Providers: These are companies willing to offer access to storage and software. Significant examples of service providers include:

  • Alibaba Cloud

  • Amazon Web Services (AWS)

  • Google Cloud Platform (GCP)

  • Microsoft Azure

Cloud Deployment Models

Cloud deployment models define the setup, management, and availability of cloud services. They determine the specific access rights of users and how resources are shared among them.

Public Cloud (Off-site)

• Characteristics: Services are offered to the general public over the internet and are managed by third-party providers such as Google Cloud or AWS.

• Location: It is considered "off-site" because it is located in a remote location and is not on-site for the user.

• Ownership: Users can utilize these services remotely via the internet without the necessity of owning the underlying hardware or software.

• Examples:

  • Web-based email: Gmail, Outlook, Yahoo Mail.

  • Online office applications: Microsoft Office 365, Google Docs, Google Sheets, and Google Slides.

  • Cloud storage: Dropbox, OneDrive, Google Drive.

Private Cloud (On-premises)

• Characteristics: Typically utilized by a single organization. It can be managed by the organization itself or by a third-party provider.

• Location: Termed "on-premises" (or on-site), meaning it is located within the organization’s physical location.

• Target Use Case: Ideal for organizations requiring high levels of security and a greater degree of control over their computing environment.

• Examples: Banks, healthcare organizations, and government agencies.

Community Cloud

• Characteristics: Used by multiple organizations from the same "community" that share common needs. Features include:

  • It is not a public cloud because access is restricted to the specific community.

  • It is not a private cloud because more than one organization is involved in usage.

  • Management can be handled by the organizations themselves or by a third party.

• Examples:

  • Companies or industries with shared requirements.

  • Multiple government agencies with common needs.

  • Clusters of banks sharing resources to collaborate securely.

  • Healthcare hospitals exchanging patient data securely while adhering to healthcare regulations.

  • Universities or educational institutions collaborating to host research data, educational tools, and resources.

Hybrid Cloud

• Characteristics: A combination of both public and private clouds, allowing data and applications to be shared between the two. It links computing resources from on-premises (private) and off-site (public) locations to function as a single system.

• Example 1: Online Banking Hybrid Cloud:

  • Private Cloud component: Banks store highly sensitive customer data such as account balances and personal information.

  • Public Cloud component: Used for non-sensitive services like mobile banking application interfaces and websites.

  • Hybrid interaction: When a user logs in, the public cloud delivers the interface quickly, while the private cloud manages secure transaction processing and sensitive data retrieval.

• Example 2: Education System Hybrid Cloud:

  • Private Cloud component: A university stores student records, including personal info, academic performance, and financial details.

  • Public Cloud component: Hosting an e-learning platform such as Moodle.

  • Hybrid interaction: When a student logs into Moodle (public), the platform fetches those academic records from the private cloud to check the student's eligibility.

Cloud Service Models

Cloud service models represent the various types of computing resources offered by a provider. They define what is provided to the user and how those services are managed.

Software as a Service (SaaS)

• Description: Provides access to fully managed software applications over the internet as a service. Infrastructure, updates, and maintenance are handled by the provider.

• Key Features: Users do not need to install software on their devices; they access it via a web browser. The third-party provider handles all online updates.

• Target Audience: End-users and businesses. This model offers the least amount of control to the user.

• Examples: Google Docs, Google Maps, Gmail, and Microsoft Office 365.

Platform as a Service (PaaS)

• Description: Provides customers with tools to develop, run, and manage applications while the provider manages the underlying infrastructure, including operating systems and servers.

• Key Features: The provider hosts the hardware and software on its infrastructure and offers services for development, testing, deployment, and hosting. Developers can build and test apps without managing servers.

• Target Audience: Software developers and IT departments needing a platform for applications.

• Examples: Google App Engine and Heroku.

Infrastructure as a Service (IaaS)

• Description: The most basic cloud service model, providing essential resources like virtual machines, networking, and storage.

• Key Features: Users can rent virtual servers and storage, and they have the ability to install and manage the software they need. This provides the most control over resources but requires the most user-led management and maintenance.

• Target Audience: IT administrators.

• Examples: Amazon Web Services (AWS), Microsoft Azure, and Google Cloud Platform (GCP).

Comparative Analogies for Cloud Service Models

Transportation Analogy

• On-premises IT Infrastructure: Like owning a car. You are responsible for everything.

• IaaS: Like leasing a car. You choose the car and drive it where you want, but you do not own it.

• PaaS: Like taking a taxi. You do not drive; you simply tell the driver the destination and relax in the back seat.

• SaaS: Like going by bus. The bus has an assigned route, and the ride is shared with other passengers.

Pizza Analogy

• On-premises IT Infrastructure: Making a pizza at home from scratch.

• IaaS (Take Everything And Bake): A delivery service provides all ingredients and the use of a rented kitchen (oven, fridge, tools), but you must prepare, assemble, and cook it yourself.

• PaaS (Making the Pizza yourself): You are given pre-made dough, sauce, and toppings, which you then assemble and cook in a provided oven.

• SaaS (Ready-Made Pizza): Like ordering a pizza from a restaurant where it is cooked and sliced. You simply enjoy the pizza with no work required.

Cloud Computing: Scenarios and Use Cases