A buffer amplifier is an electronic circuit that isolates different stages of a system while maintaining signal integrity. It typically has a high input impedance and a low output impedance, allowing it to prevent loading effects on the previous stage. This makes it useful in applications where signal strength needs to be preserved without distortion. Buffer amplifiers are commonly used in various devices, including audio equipment, sensor interfaces, and data acquisition systems. They can also serve as voltage followers, ensuring that the output voltage closely follows the input voltage, which is essential for accurate signal processing.