Hadoop Sequence documents are one of the Apache Hadoop specific file formats, which store information in the serialized key-value combine. Hadoop Sequence File is utilized as a part of Map Reduce as input/output formats. By default Mapper output is stored on local document framework, which is in Mapper node. Outputs of Maps are put away utilizing Sequence File. Inside Hadoop utilizes Sequence File organize for the Mapper which is stored in the local document system. In general, Apache Hadoop supports text records which are normally utilized for keeping and storing the information, other than the text documents it additionally supports binary documents and one of these binary formats are called Sequence records.