Book excerpt: Based on The International Metrology Congress meeting, this reference examines the evolution of metrology, and its applications in industry, environment and safety, health and medicine, economy and quality, and new information and communication technologies; details the improvement of measurement procedures to guarantee the quality of products and processes; and discusses the development of metrology linked to innovating technologies. The themes of the Congress (quality and reliability of measurement, measurement uncertainties, calibration, verification, accreditation, sensory metrology, regulations and legal metrology) are developed either in a general way or applied to a specific economic sector or to a specific scientific field.