Flexibility. Scalability. Reliability.
Essentially, the cloud allows IT shops to reduce CAPEX and engage in low risk development. IaaS can be thought of as 'rented hardware' that enterprises can access instantly with little upfront cost, providing them with the computing, storage and networking functions for existing services or new projects.
Microsoft Azure is the Microsoft public cloud platform that enables you to quickly build, deploy, scale and manage servers, services and applications across a global network of data centers. You can build applications using multiple languages, tools and frameworks.