The glib answer is that a cloud provider understands the need for a private network.
But, in that is a deeper truth: a VPS is a cheaper machine. It becomes "cloud" when you use many machines together. If you're using many machines, you really want intercommunication between those machines to be easy, fast and - yes - reasonably secure.
But, in that is a deeper truth: a VPS is a cheaper machine. It becomes "cloud" when you use many machines together. If you're using many machines, you really want intercommunication between those machines to be easy, fast and - yes - reasonably secure.