Which of the following best defines cloud computing?

Cloud computing is best defined as a model for enabling ubiquitous access to shared resources. This definition emphasizes the essential characteristics of cloud computing, which include on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service.

In this model, users can access shared resources such as servers, storage, applications, and services over the internet without having to manage the physical hardware directly. This provides significant advantages, including cost efficiency, scalability, and flexibility, as resources can be allocated and scaled according to user needs, and accessed from anywhere with an internet connection.

The other options do not capture the essence of cloud computing. Storing data on physical devices refers to traditional methods of data management, which do not have the same accessibility or scalability as cloud solutions. A traditional server-based infrastructure lacks the flexibility and resource sharing characteristic of cloud models. A type of local area network technology is also more restrictive, as it pertains to specific networking setups, unlike the broader, more flexible nature of cloud computing.