The development of automotive electrical and electronic systems has evolved from simplicity to complexity. Early vehicles were equipped with basic circuits for ignition and lighting. In the mid-20th century, with the rise of semiconductor technology, voltage regulators and transistor ignition systems were gradually adopted. After the 1980s, the microprocessor revolution drove the widespread use of electronic control units (ECUs), enabling the digital control of core components such as engines and transmissions. In the 21st century, the development of in-vehicle network architectures and intelligent sensors made distributed electronic systems possible, leading to the emergence of 48V mild hybrid systems and high-voltage electrical platforms. Currently, automotive electrical and electronic systems are evolving toward domain controller architectures, supporting advanced driver-assistance systems (ADAS) and connected vehicle functions. Their complexity has surpassed that of traditional mechanical systems, becoming the technological core of modern vehicles.