The internet isn’t what we think. It is physical, subject to the vagaries of nature and time, just as our bodies are. Like us, it will flicker and fade. The internet’s fragility crops up everywhere: in the sudden disappearance of a relied-upon website, and in the endless thrum of posts, images, and videos.
The cloud is a great metaphor. It represents all that software that we expect to just “be there”, without any thought to where it might be. Of course software needs a platform to run on, but it is designed so it doesn’t matter where it is run. Your phone just finds it. It couldn’t care less where the server is, it just connects, and you get your cat pictures, as long as you are connected to the Internet.
The physical manifestation of the cloud is all those servers in datacenters, with redundant connectivity and power, designed to run and be connected 24/7/365.26 . They are designed with failures and redundancy in mind. It can take a literal act of war to get a datacenter off the network permanently. And even then, when local data and connectivity are lost, people running Web services for real should be backing their data up offsite and designing their services to easily spin up elsewhere. Some services hosted in those datacenters simply had a brief outage while other resources were provisioned.
“The Cloud” is really just a series of Best Practices for software design and operations so that these services can run anywhere. Of course, they have to run somewhere, but they can run anywhere…