Description: InputFormat in Hadoop is a fundamental abstraction that defines how input data is split and read in a MapReduce job. Its main function is to manage how data is distributed across different nodes in the cluster, ensuring that each mapping task receives the appropriate amount of data to process. InputFormat is responsible for reading data from various sources, such as files in HDFS (Hadoop Distributed File System) or other distributed storage systems, and converting it into a format that can be processed by the MapReduce framework. There are different implementations of InputFormat, such as TextInputFormat, which is used to read text files, and SequenceFileInputFormat, which is used to read binary sequence files. Each implementation has specific characteristics that allow for optimizing data processing based on the type of input. Choosing the right InputFormat is crucial for the performance of the MapReduce job, as it influences processing efficiency and resource utilization in the cluster. In summary, InputFormat is a key component in the Hadoop ecosystem, facilitating the ingestion and handling of large volumes of data, enabling organizations to extract value from their data effectively.