Platform as a Service

In a PaaS environment, the cloud provider maintains the physical infrastructure, physical security, and connection to the internet, maintain the operating systems, middleware, development tools, databases, and business intelligence services that make up a cloud solution.
In a PaaS scenario, you don't have to worry about the licensing or patching for operating systems and databases.
PaaS is well suited to provide a complete development environment without the headache of maintaining all the development infrastructure.

Shared responsibility model

PaaS splits the responsibility between you and the cloud provider.
Depending on the configuration, you or the cloud provider may be responsible for networking settings and connectivity within your cloud environment, network and application security, and the directory infrastructure.

Development framework: PaaS provides a framework that developers can build upon to develop or customize cloud-based applications. Cloud features such as scalability, high-availability, and multi-tenant capability are included, reducing the amount of coding that developers must do.
Analytics or business intelligence: Tools provided as a service with PaaS allow organizations to analyze and mine their data, finding insights and patterns and predicting outcomes to improve forecasting, product design decisions, investment returns, and other business decisions.