In the recent years, the field of „big data? has emerged as the new frontier in the wide spectrum of IT-enabled innovations and opportunities due to the information revolution. The ever-increasing creation of massive amounts of data through diversified data generating sources has prompted industry as well as academics to intensify their attention to harness and analyze big data. Big data technologies are maturing to a point in which more organizations are adapting big data as a core component of the information management and analytics infrastructure. Big data, as a compendium of emerging disruptive tools and technologies, emerged as the next big technological idea enabling integrated analytics in many common business scenarios. The objective of this paper is to give a comprehensive overview of challenges and opportunities of big data. This paper discuss in detail about various characteristics of big data and how to overcome the challenges posed by them. It also discusses various machine learning and data mining algorithms used to uncover hidden patterns in large datasets and how the big data analytics can help in various fields to take insightful decisions. © Research India Publications.