OpenShift is a Platform as a Service (PaaS) developed by Red Hat, built on standard Linux technology, offering various licensing options such as OpenShift Origin (free), OpenShift Enterprise (paid), and a Red Hat-hosted cloud service. It utilizes 'gears' as containers with resource limits for running applications, and 'cartridges' to support multiple programming languages and databases. OpenShift enables application management through command-line tools and provides benefits like flexible stacks, scalable applications, and a secure, non-virtualized environment for code deployment.