Big data refers to extremely large data sets that are difficult to process using traditional data processing tools. It is characterized by volume, velocity, variety, veracity and variability. Big data can be structured, unstructured or semi-structured. It comes from a variety of sources and must be analyzed in real-time. A big data platform must be able to handle different data types and volumes at large scale from diverse sources, perform analytics and enable discovery. The five characteristics that define big data are volume, velocity, variety, veracity and variability.