Cloud computing is a model that enables convenient access to a shared pool of configurable computing resources. It provides on-demand self-service, broad network access, resource pooling, rapid elasticity, and measured service. Cloud computing has three main service models - Software as a Service (SaaS), Platform as a Service (PaaS), and Infrastructure as a Service (IaaS). It also has four deployment models - private cloud, community cloud, public cloud, and hybrid cloud. Hadoop is an open-source framework for distributed storage and processing of large datasets across clusters of commodity hardware. It was developed to address the need to process big data at a reasonable cost and time.