Which type of computing performs computation, storage, and even complete applications as a service delivered across a network?

Introduction / Context:
Modern information technology increasingly relies on delivering computing resources as services over networks. Instead of owning all hardware and software locally, organisations and individuals can rent processing power, storage, and applications from remote data centres. This question checks if you know the standard term used when computation, storage, and entire applications are provided as on demand services over the internet or a similar network.

Given Data / Assumptions:

• The description includes computation, storage, and applications.
• These are delivered as services rather than local installations.
• Access is across a network, typically the internet.

Concept / Approach:
Cloud computing is the widely accepted term for delivering computing resources as services over a network. In cloud computing, providers offer infrastructure, platforms, and software as services, commonly called IaaS, PaaS, and SaaS. Users access these services over the internet without needing to know the details of the underlying hardware. Distributed computing and parallel computing focus on how computation is organised internally, not on the business model of delivering resources as services. Virtual computing refers to virtualisation technology rather than the service delivery model itself.

Step-by-Step Solution:
Step 1: Identify that the question emphasises computation, storage, and applications delivered as a service. Step 2: Recall that cloud computing is defined as on demand network access to shared computing resources that can be rapidly provisioned with minimal management effort. Step 3: Note that distributed and parallel computing mainly describe how multiple computers cooperate to solve problems, not how those resources are sold or rented as services. Step 4: Recognise that virtual computing relates to creating virtual machines and virtual environments and is a technique used inside data centres, including clouds. Step 5: Therefore, the only option that directly captures the idea of computing delivered as a service across a network is cloud computing.

Verification / Alternative check:
Look at common examples such as web based email, online document editing, or renting virtual servers from a cloud provider. These services provide storage, processing, and complete applications through a browser or client over the internet. Marketing material and technical documentation consistently label these solutions as cloud services or cloud computing offerings. This confirms that cloud computing is the correct match for the description in the question.

Why Other Options Are Wrong:
Distributed computing: This is wrong because it describes a style of computation spread across multiple nodes but does not necessarily mean that resources are delivered as pay per use services over a public network.
Parallel computing: This is wrong because it focuses on concurrent execution of tasks to increase speed, not on delivering applications, storage, or processing as services.
Virtual computing: This is wrong because virtualisation enables creating virtual machines and virtual networks, but by itself does not mean that resources are offered as remote cloud services to external users.

Common Pitfalls:
Students sometimes confuse internal technical architectures with service models. Distributed and parallel systems may exist inside a cloud, but the exam phrase performs computation, storage and even applications as a service points specifically to cloud computing. Another pitfall is thinking that any use of virtual machines automatically implies cloud computing, but virtualisation can also be local. Focus on the as a service idea to avoid confusion.

Final Answer:
The described model is known as Cloud computing.