Microsoft Azure is a cloud computing platform offering various services including computing, storage, databases, and web hosting. Azure operates out of 32 regions worldwide. It offers three main service models: Infrastructure as a Service (IaaS), Platform as a Service (PaaS), and Software as a Service (SaaS). App Service is a PaaS offering that allows users to build, deploy, and manage web applications, REST APIs, mobile back ends, and web jobs. Traffic Manager helps distribute user traffic between different endpoints for availability and performance. It uses DNS to route clients to the optimal endpoint based on factors like location and health.