Simply put, a cloud management platform is a piece of all-in-one software with integrated tools that provide a unified platform for provisioning, management, billing, control, and governance of resources across different types of cloud deployments, such as private and public, and virtualized infrastructures.
A more formal definition of a cloud management platform is well made by Gartner, which is a global research company in America.
Gartner defines a cloud management platform as:
Integrated products that provide for the management of public, private and hybrid cloud environments. The minimum requirements to be included in this category are products that incorporate self-service interfaces, provision system images, enable metering and billing, and provide for some degree of workload optimization through established policies. More-advanced offerings may also integrate with external enterprise management systems, include service catalogs, support the configuration of storage and network resources, allow for enhanced resource management via service governors and provide advanced monitoring for improved "guest" performance and availability.
The source is http://www.gartner.com/it-glossary/cloud-management-platforms.
According to Gartner, when choosing a cloud management platform, here are some capabilities to look for: