More accurately, it's someone else's network of pluggable computers. "The cloud" is just a convenient metaphor for "it's up there,where someome else keeps it working".

The point is to free up resources in individual companies that would otherwise be used maintaining the infrastructure.

In a lot of companies that translates to having fewer employees to pay. Enlightened companies keep those people and allocate them to other, profitable, activities.

A wonderful and Powerful effect of vitualization is the idea of declarative infrastructure. Individual companies can allocate those Cloud resources in specialized ways. It's primary value is in economies of scale.