Apache Hadoop is an open-source framework for distributed storage and processing of large datasets. It is designed to handle big data across clusters of computers using its core components: HDFS (Hadoop Distributed File System) and MapReduce. Hadoop supports scalability, enabling organizations to process petabytes of data efficiently. It integrates with tools like Apache Hive and Spark for advanced analytics and data querying. Hadoop is widely used in industries like finance, healthcare, and retail for big data applications.