Nielsen Holdings is a global leader in **audience measurement, data, and analytics**, providing critical insights into consumer behavior and media consumption worldwide. Founded in 1923 by Arthur C. Nielsen, Sr., the company pioneered market research by introducing the first retail measurement system, enabling businesses to understand market share and consumer purchasing patterns—concepts that revolutionized marketing and sales strategies[1][2]. Headquartered in New York, Nielsen operates in over 100 countries, covering more than 90% of the global GDP and population[2][3]. Nielsen’s business is organized into three main segments: **What Consumers Buy**, **What Consumers Watch**, and **Expositions**. The Buy segment offers retail transactional data and analytics, helping consumer packaged goods companies optimize brand management, product launches, sales analysis, and marketing strategies[1]. The Watch segment provides media and advertising industries with detailed viewership data across television, online, and mobile platforms, enabling clients to understand audiences, value advertising inventory, and optimize ad spending[1][2]. The Expositions segment manages business-to-business trade shows and events primarily in the U.S.[1]. Over the decades, Nielsen has evolved with the media and technology landscape, expanding from traditional TV ratings to cross-platform audience measurement that includes digital and mobile media[2][4][5]. It has divested its NielsenIQ consumer intelligence arm in 2021 to focus more on media measurement and analytics[2]. The company employs around 44,000 people globally and is recognized for its leadership in diversity, inclusion, innovation, and sustainability practices[3][6]. Nielsen’s innovations continue to shape the future of media by delivering **real audiences, real data, and real decisions**, empowering clients to unlock marketing value and adapt to shifting consumer habits across multiple channels[5]. Its commitment to responsible business practices and ESG principles reinforces its role as a trusted partner in the evolving media and consumer landscape[6].