Final answer:
The Internet is depicted as a cloud as a metaphor for its complex, abstracted network infrastructure, similar to how clouds obscure our view of the sky. This illustration simplifies the representation of the Internet's physical components and is also apt for cloud computing.
Step-by-step explanation:
The Internet is often depicted as a cloud because it represents the complex network infrastructure in a simplified way, where the specifics of the physical network (servers, cables, data centers, etc.) are not important to the understanding of the concept by the general public.
Just like how clouds in the sky obscure our view of what's beyond, the complexities of the Internet's infrastructure are abstracted away when we look at the 'cloud'. This abstraction is fitting, as many aspects of the Internet are ethereal and dispersed through a myriad of devices and locations, offering ubiquitous access much like the seemingly all-encompassing nature of clouds in the atmosphere.
The use of the cloud symbol has become even more appropriate with the advent of cloud computing, where data and applications are hosted remotely ('in the cloud'), providing on-demand access to resources.