Big Data" is a term that have jumped overnight from its roots. It can be described as an innovative technique and technology to save, distribute, manage, visualize and analyze larger-sized data with extreme velocity and methods to manage unstructured and structure incapable amount of data. Big data has high capacity to predict conclusion, with low cost consumption, increase efficiency and enhance decision-making in various fields like traffic control ,weather prediction , disaster prevention, finance management, fraud control, improve business transaction, control on national security, education improvement, and health care. Analyzing Big Data is a challenging task as it involves large distributed file systems which should be fault tolerant, flexible and scalable. Various technologies can be used to handle the big data. These technologies handle massive amount of data in MB, PB, YB, ZB, KB, and TB.