Azure is a cloud service or platform that helps in constructing, managing and establishing applications through data centers. Azure provides Platform as a Service (PaaS), Infrastructure as a Service (IaaS), and Software as a Service (SaaS) for storage, networking, and analytics. It provides PaaS that allows developers to create various applications. With the help of IaaS, multiple users can use the same server. Azure as SaaS allows users to access their required data from any device.
To get a better understanding about Azure, you can go through the Microsoft Azure Tutorial. You could also watch ‘What is Azure?’ video below to gain insight into the concept: