This chapter introduces the foundational framework for modeling and control of mass–stiffness–damping systemsMass–stiffness–damping system (MKC systemsMKC system), a class of dynamic systems governed by second-order differential equationsSecond-order differential equation that are pervasive in engineering and industrial applications. These systems characterize the dynamics of structures, actuators, and physical processesPhysical process across robotics, aerospace, automotive, civil engineering, and energy systems. The chapter begins with a formal description of MKC systemsMKC system and illustrates their relevance through practical examples—ranging from vehicle suspensions and robotic manipulators to rotating machineriesRotating machinery and wind turbinesWind turbine. With a growing demand for high-performance, reliable, and adaptive control under uncertainty, the chapter outlines both classical and advanced control strategies used to address the intrinsic challenges of nonlinearity, coupling, and parameter variabilityParameter variability in MKC systemsMKC system. The current industrial and academic focus areas are identified, including active suspension systemsActive suspension system, autonomous vehicles, smart infrastructure, and precision manufacturingPrecision manufacturing. The limitations of conventional controls are discussed, motivating the transition to robust, adaptive, and intelligent control paradigms. A preview of the structure of this book is provided, highlighting a practical and progressive approach to modeling, control design, and robustness enhancement. This chapter sets the stage for a deeper exploration of scalable, model-based control techniques suited for real-world, complex MKC systemsMKC system.