A successive approximation ADC (Analog-to-Digital Converter) is a type of converter that digitizes an analog signal by using a binary search algorithm. It compares the input voltage to a reference voltage and adjusts a digital output bit by bit, starting from the most significant bit. This process continues until the digital representation closely matches the input signal. This method is efficient and commonly used in applications requiring moderate speed and resolution, such as in microcontrollers and digital signal processing. Successive approximation ADCs balance speed and accuracy, making them suitable for various electronic devices and systems.