2.1.8 Web and Cloud Services
The Internet provides the communication infrastructure used by many services. Two important examples are the World Wide Web and cloud computing. They both rely on networks, but they solve different problems.
This section distinguishes the Internet from the Web, explains how linked web resources are organised, and evaluates public and private cloud services.
By the end of this section, you should be able to:
- distinguish the Internet from the World Wide Web;
- describe websites, web pages and hyperlinks;
- explain the main idea of cloud computing;
- compare public and private clouds;
- identify infrastructure, platform and software cloud services;
- evaluate benefits and drawbacks of cloud computing;
- justify a suitable cloud arrangement for a given organisation.
The Internet and the World Wide Web
The words Internet and World Wide Web are often used as though they mean the same thing. They are closely connected, but they describe different layers of the system.
| Term | What it is | Example |
|---|---|---|
| Internet | A global system of interconnected networks that carries data between devices and organisations. | Provider networks, routers, fibre links, mobile networks and local networks. |
| World Wide Web | A service that uses the Internet to deliver linked documents and other resources. | Browsing a school website, reading an online article or opening a web application. |
One infrastructure, many services
The Web is only one service using the Internet. Email, file transfer, online gaming, voice calls and cloud storage also use Internet infrastructure, but they are not all part of the World Wide Web.
Common mistake
Do not define the Internet as “all the websites”. Websites belong to the Web, while the Internet is the network infrastructure that carries their data.
How the Web is organised
Web page: one document or interface within a website.
Hyperlink: a selectable reference that leads to another resource.
A user normally interacts with the Web through a browser. The browser requests a resource, receives the returned data and presents the page. A hyperlink gives the browser the information needed to request a different resource.
Example journey
- A student opens the homepage of a revision website.
- The browser requests the page from a web server.
- The server returns the page content.
- The student selects a hyperlink labelled Practice quiz.
- The browser requests the linked resource and displays the new page.
Exam tip
When comparing the Internet and the Web, explain the relationship: the Internet provides the communication infrastructure, while the Web is one service that uses it to deliver linked resources.
Cloud computing
Cloud computing provides computing resources from remote systems rather than relying entirely on hardware and software located beside the user.
What can be provided?
- storage for files, backups and databases;
- processing power for demanding tasks;
- development and testing environments;
- applications accessed through a browser or client program;
- shared services used by staff in different locations.
Typical request path
The user still needs a suitable device and network connection, but the main computation or storage may take place in the provider's data centre.
Public and private clouds
| Comparison point | Public cloud | Private cloud |
|---|---|---|
| Who operates it? | An external cloud provider. | One organisation or a provider acting only for that organisation. |
| Who uses it? | Many unrelated customers share the provider's overall infrastructure. | Access is reserved for one organisation. |
| Control | The provider controls much of the underlying system. | The organisation has greater control over configuration and policy. |
| Cost model | Often charged according to usage or subscription. | Usually requires greater dedicated investment or management. |
| Scaling | Resources can often be increased quickly. | Expansion depends on the capacity reserved for the organisation. |
| Data governance | The organisation must trust the provider's controls and contractual arrangements. | Data handling can be designed around the organisation's own requirements. |
Common mistake
“Private cloud” does not simply mean that a user has a private folder. It means the cloud environment is reserved for one organisation.
Cloud service models
Cloud services can be grouped by how much of the computing system is managed by the provider. These categories are useful supporting knowledge.
| Service model | What the provider supplies | What the customer mainly controls | Original example |
|---|---|---|---|
| Infrastructure as a Service (IaaS) | Virtual machines, networking and storage. | Operating systems, applications and data. | A research team rents extra servers for a simulation project. |
| Platform as a Service (PaaS) | A managed environment for building and deploying software. | Application code and data. | Students deploy a web application without configuring a server operating system. |
| Software as a Service (SaaS) | A complete application delivered remotely. | User settings, content and access permissions. | A company uses an online collaboration suite through a browser. |
Exam tip
The syllabus priority is public/private clouds and their advantages and disadvantages. Use IaaS, PaaS and SaaS only when they help explain the type of service being provided.
Benefits and drawbacks of cloud computing
| Feature | Possible benefit | Possible drawback |
|---|---|---|
| Remote access | Authorised users can work from different locations and devices. | Access depends on a working network connection and provider availability. |
| Scalability | Storage or processing capacity can be increased without buying local hardware immediately. | Usage charges may rise unexpectedly when demand increases. |
| Provider-managed maintenance | The organisation needs less local hardware administration. | The customer has less direct control over updates and service changes. |
| Shared infrastructure | The provider can operate large systems efficiently. | Customers must trust the provider to isolate data and services securely. |
| Centralised data | Users can collaborate on consistent versions and backups can be managed centrally. | A provider failure, account compromise or configuration error can affect many users. |
| Subscription or usage pricing | Reduces the need for a large initial hardware purchase. | Long-term costs may exceed the cost of owning a stable local system. |
Security and privacy are not simple yes/no issues
A professional cloud provider may offer strong physical security, redundancy and specialist staff. However, the customer still has responsibilities such as configuring access correctly, choosing strong authentication and deciding which data are suitable to store remotely.
Common mistake
Avoid claiming that cloud computing is automatically secure or automatically insecure. Security depends on provider controls, customer configuration, user behaviour and the sensitivity of the data.
Interactive decision lab
Open each scenario, choose a cloud arrangement, and compare your reasoning with the model response.
Scenario A: A small animation studio needs powerful rendering hardware for six weeks.
Possible choice: public cloud infrastructure. The studio can rent processing capacity for the project instead of buying servers that may be underused afterwards. The team must monitor usage charges and protect uploaded project files.
Scenario B: A hospital wants remote access to highly sensitive records under strict internal controls.
Possible choice: private cloud. A dedicated environment gives the hospital greater control over access, policy and data handling. It will require more specialist management and may cost more than a shared public service.
Scenario C: A new charity needs email, document sharing and video meetings for twenty staff.
Possible choice: public SaaS. The charity can use complete online applications without operating its own servers. It should evaluate recurring cost, account security and the provider's data-handling terms.
Scenario D: A school programming club wants to deploy small web apps without managing server software.
Possible choice: public PaaS. The platform can provide deployment tools and runtime services, allowing students to focus on code. The club becomes dependent on the platform's supported tools and service availability.
Reasoning structure
Requirement → cloud feature → practical consequence → trade-off
Practice
Core understanding
- Explain the difference between the Internet and the World Wide Web.
- Describe the relationship between a website, a web page and a hyperlink.
- Explain what is meant by cloud computing.
- State two differences between a public cloud and a private cloud.
- Identify the cloud service model used when a complete application is accessed remotely.
- Explain two benefits and two drawbacks of cloud computing.
Apply your understanding
- A start-up needs temporary computing capacity for product testing. Recommend a cloud arrangement and justify it.
- A government department must keep sensitive data within a tightly controlled environment. Recommend a cloud arrangement and justify it.
- A company moves its collaboration software to the cloud. Explain one operational benefit and one new dependency.
- Explain why a public cloud can reduce initial cost but still create financial risk.
Review
| Concept | Key idea |
|---|---|
| Internet | The interconnected network infrastructure. |
| World Wide Web | A service of linked resources delivered using the Internet. |
| Public cloud | A provider-operated cloud service available to many customers. |
| Private cloud | A cloud environment reserved for one organisation. |
| IaaS | Remote infrastructure such as virtual machines and storage. |
| PaaS | A managed platform for developing and deploying applications. |
| SaaS | A complete application delivered as a remote service. |
Quick self-check
- Can I explain why the Web is not the Internet?
- Can I distinguish a website, page and hyperlink?
- Can I compare public and private clouds?
- Can I explain a benefit and drawback as consequences rather than isolated labels?
- Can I justify a cloud choice from a scenario?