Apache Hadoop
Apache Hadoop is an open-source software framework for distributed storage and processing of large datasets across clusters of computers using simple programming models. It is designed to scale up from single servers to thousands of machines, each offering local computation and storage. Hadoop's core components include the Hadoop Distributed File System (HDFS) for storage and MapReduce for processing.
Developers should learn Hadoop when working with big data applications that require processing massive volumes of structured or unstructured data, such as log analysis, data mining, or machine learning tasks. It is particularly useful in scenarios where data is too large to fit on a single machine, enabling fault-tolerant and scalable data processing in distributed environments like cloud platforms or on-premise clusters.