Big data is revolutionizing the world in the internet age. The wide variety of areas like online businesses, electronic health management, social networking, demographics, geographic information systems, online education, etc. are gaining insight from big data principles. Big data is comprised of heterogeneous datasets which are too large to be handled by traditional relational database systems. An important reason for explosion of interest in big data is that it has become cheap to store volumes of data and there is a major rise in computation capacity. This chapter gives an overview of big data ecosystems comprising various big data platforms useful in today's competitive world.