A cloud based server is maintained by a cloud services provider and accessed through the internet. It is a virtual server which means that it is implemented in software rather than being a physical device with the server hardware on which it runs operated by the provider.
A cloud server has many benefits, not least of which is that users need not be concerned with implementing it and maintaining the hardware on which it runs. In addition the cloud provider offers users service level guarantees that ensure it is always available and any problems are addressed immediately. The cost of using a server in a cloud computing environment is significantly lower than a business expending capital to buy it and the cost of operating it; cloud services are charged on a subscription model where users only pay for the computing services they use.