Quantitative techniques are statistical and programming methods that help decision makers analyze problems, especially business problems, using quantitative data. They have evolved from early applications in the 19th century to today where they are used widely. They can be classified into statistical techniques, which analyze collected data, and programming techniques, like linear programming, that model relationships to find optimal solutions. Quantitative techniques help businesses with tasks like resource allocation, strategy selection, and decision making. However, they have limitations like not accounting for intangible human factors.