Big data is any collection of data sets so large and complex that it becomes difficult to process using traditional data processing applications. Big data "size" is from a few dozen terabytes to many petabytes of data. Big data is a set of techniques and technologies to mine large hidden values from large data sets that are diverse, complex, and of a massive scale. A McKinsey report suggests suitable technologies include crowd sourcing, data fusion and integration, genetic algorithms, machine learning, natural language processing, signal processing, simulation, time series analysis, data mining and visualization. Big data can be described by the following characteristics, volume, variety, velocity, variability and complexity. Many domestic and foreign big data examples are presented to easily explain a concept and applications of big data analytics. Also, several case studies for big data analytics and applications in battery, it & electric materials and petrochemical company in LG Chem are introduced.