Big data refers to vast datasets that are challenging to manage with traditional tools, posing difficulties in areas like capture, storage, and analysis. The document discusses the evolution of big data, highlighting its exponential growth due to increased information capture from multimedia, social media, and IoT, and emphasizes the need for effective data handling in business. Additionally, it explores the implications of big data on customer behavior, requiring companies to adapt to complex consumer interactions while leveraging data for enhanced insights and decision-making.