The Serial Peripheral Interface (SPI) Bus is a synchronous serial communication interface used for short-distance communication primarily in embedded systems. It allows multiple devices to communicate with each other using a master/slave architecture, where the master initiates and controls the communication. The SPI interface uses a set of four wires (MOSI, MISO, SCLK, and SS) to transmit data between devices, and can support multiple slave devices on the same bus. SPI is commonly used for communication between microcontrollers, sensors, and memory devices.