This chapter provides a comprehensive examination of information-measuring systems (IMSs), spanning their historical evolution, theoretical basis, and practical implementation. It contextualizes the importance of measurement within the development of mathematics, science, and technology, defining the fundamental areas of metrology and the complexity of measurement tasks. Drawing from a multidisciplinary approach involving signal and systems theory, information transmission, and quantum mechanics, the chapter delves into the classifications, hardware, and software components of IMS, from early microelectronic systems to modern adaptive, virtual, and intelligent configurations. Emphasis is placed on the transition from error-centered to uncertainty-centered measurements in international metrology, reflecting evolving standards. Specific attention is given to the theoretical foundations, life cycle stages, and accuracy of measurements, underpinning the design and development processes of IMS. Additionally, the paper incorporates advancements in measurement technologies, emphasizing their critical role in current and future applications across diverse fields such as economy, science, and technology. Through a detailed exploration of IMS classifications and functional characteristics, the chapter underscores the ongoing need for innovation and enhancement in measurement systems to address emerging scientific and technological challenges.