Real-Time Applications are applications that operate within an immediate time frame; sensing, analyzing, and acting on streaming data as it happens. This is in contrast to a database-centric application where information is ingested and stored in a database (in the cloud or on-premise) for future analysis.
Most real-time applications rely on an event-driven architecture (EDA) to allow for asynchronous processing of streaming data. These applications are vital in industries where operating within a specific time constraint can mean life or death; such as identifying and repairing a gas leak at an oil refinery or locating a lost child at a public park.