Big data was first used by Doug Laney, an Industrial analyst, in 2001. He further articulated that the Big Data was a kind of data, which is large, fast or complex, and difficult to process using traditional methods. He viewed that the Big Data was largely depending on three V’s–Volume, Velocity and Variety. The volume is the collection of data from a variety of sources such as Smart IoT devices, videos, industrial equipment, business transactions and social media. In the past, storing such data was a hectic problem to control, but cheaper storage platforms, such as data lakes and Hadoop (an open-source software), have eased the burden now. In the age of the Internet with unprecedented speed, the Velocity of data has become a hectic job to control it promptly. To organize them in the manner of a sequence that becomes a dream to overcome. RFID tags, sensors and smart meters are good examples. Variety means the shapes or formats of data that comes in structured and unstructured forms, such as emails, videos, audios, financial transactions, etc. The Big Data has been divided in three main formats: structured, unstructured and semi-structured. The importance of Big Data does not mean how much data you have or what you do with it, but the main purpose of such data is to what extent of the data is cost reduction, time reduction or usefulness for the developmental process. Big Data is a helpful tool for smart decision-making and helps in business-related tasks. Libraries have become the hub of research activities worldwide The Big Data has numerous sources, Most common of which are streaming data, Internet of Things and similar devices, like smart cars, industrial equipment and medical devices etc. One can analyse them on arrivals, whether to keep them or not. Social media is another source of Big Data; dealing with a large amount of data in a different format in shape of videos, images, texts and sounds as useful tools for marketing, sales and support functions etc. Some good examples are Facebook, YouTube, Instagram, etc. Other sources of Big Data are publicly available data, which come in a massive amount of open data, such as US Government data, European Union open Data portal and CIA World Fact-book etc. In emerging technology, Big Data is intertwined with different tools like smart cities, Artificial Intelligence and Internet of Things (IoT). These tools have been interconnected with different businesses, such as location-tracking, precision medicine, fraud detection and handling, advertising, entertainment and media, weather tracking, etc. In the education sector, the big data can improve student results; customise programmes; reduce dropouts and target international recruitment etc. The library is dealing with data and holds a long history of a multidimensional focus on collection, storing and organizing, preserving and providing access to information in traditional as well as in digital format both in printed and electronic material. Libraries have become the hub of research activities worldwide and people of different ages desires to get access to huge information. As data is everything in the age of information technology and the demand of people are increasing rapidly. Libraries can use big data for many reasons such as to make better decisions, create better services, GIS Mapping to get more knowledge about library customers where our non-customers live etc. Meanwhile, a librarian can buy better stuff with the help of big data. One can also track other library-related analytics. Libraries use Big Data to make better decisions and create better services. As discussed, Big Data comprised of high?velocity, high?variety and high?volume information while libraries deal with such variety, volumes and velocities. Modern libraries are stepping towards the digitisation process, which offers services in different formats such as texts, images, videos, audios and other resources. These resources require costly technologies and Big Data can help them better enhance their insight and decision-making. Academic libraries are dealing with primary and secondary data in large amounts and intent to share maximum information with the end-users. Big Data technologies can help the librarians by adding values and are regarded as useful tools for societal and macro-level activities. The role of libraries in the 21st century remains trivialised due to emerging technology and information-seeking behaviour. While launching a project of Big Data in practical, one can face several challenges, as this application has both light and dark sides. Big data advocates open access to various information which causes data security due to its openness. Hence, Big Data creates issues initially but library practitioners have a key role owing to their expertise. Libraries need corresponding and extensive skills before stepping down into big data. In this regards, Librarians may play a key role to manage large-sized datasets. The size and variety of data are increasing significantly and librarians may get proper control with the help of Big Data. In such activities, the professional librarians must ensure the quality of data for the end-users. IT and technical skills have become a need of the hour for every profession. In this regard, the four V’s of Big Data might be kept in mind before stepping in Big Data. These are Volume, Velocity, Variety and Veracity. Managing big data is a big challenge and to overcome this challenge, professional knowledge and environment should be brought under consideration, before stepping into Big Data. The writer works in the library of the Institute of Strategic Studies Islamabad (ISSI). He can be reached at abidhussain@issi.org.pk