What is Cloud Database

The National Institute for Standards and Technology (NIST) describes Cloud Computing describes as : Cloud computing is a model for simple, on-demand network access to a shared pool of configurable computing resources (like networks, servers, storage, applications and services), the can be quickly deployed with minimal administration and no interaction of the service provider.This trend of NoSQL Databases in the Cloud has developed to compensate for the weaknesses of the relational databases, in terms of scalability.
https://thecustomizewindows.com/2013/01/databases-in-the-cloud-an-abstract/