Big data refers to large, complex datasets that cannot be processed by traditional data processing software. It is characterized by high volume, velocity, and variety of data. The amount of data generated is growing rapidly due to factors like increased internet usage and proliferation of IoT devices. Big data is stored and processed using distributed systems like Hadoop and Spark, and non-relational databases. It has enabled more accurate decision making, innovations, and life-saving applications in healthcare. The big data market is forecast to grow significantly in coming years due to increased cloud computing and digital transformation initiatives.