The document provides an introduction to operations research (OR). It discusses that OR is a scientific approach to decision making and problem solving that uses techniques from areas like statistics, probability theory, and other applied mathematics. It then discusses the history and origins of OR, noting it emerged from military operations research during World War II. Several key areas where OR is applied are also outlined like national planning, defense, industrial operations, and engineering. The rest of the document defines OR and lists some of its common methodologies, tools, and limitations.