Big data is used across various industries: 1. Healthcare: Analyzing medical records and sensor data can improve disease diagnosis, treatment personalization, and drug development. 2. Finance: Big data helps detect fraudulent activity, assess creditworthiness, and make informed investment decisions. 3. Retail: Understanding customer behavior through big data allows retailers to personalize recommendations, optimize product placement, and improve supply chain management. 4. Social Media: Social media platforms use big data to personalize user feeds, target advertising, and track brand sentiment.