Hadoop YARN is a resource management layer introduced in Hadoop 2.0, designed to address the limitations of the earlier MapReduce framework by separating resource management from data processing. It acts as a central authority that allocates resources (CPU, memory) to various applications running on a Hadoop cluster, enabling multiple data processing engines like MapReduce, Spark, and Tez to run on the same cluster. YARN's key components include the ResourceManager, NodeManager, ApplicationMaster, and containers, which work together to allocate resources and execute tasks across the cluster. By leveraging YARN's resource management capabilities, organizations can optimize their data processing pipelines, resulting in faster insights and improved decision-making. YARN has been adopted by organizations across various industries to tackle big data challenges, including big data analytics, data warehousing, real-time streaming, machine learning, and job scheduling.