The document summarizes the history and components of electronic fuel injection (EFI) systems. It discusses: 1) The development of fuel injection from the late 1880s to the introduction of the first commercial EFI system in 1957. 2) The main parts of EFI systems including fuel injectors, fuel pump, air flow meter, throttle body, and electronic control unit. 3) How the EFI system works by using engine sensors to monitor conditions and fuel injectors to precisely control the amount of fuel delivered based on information from the electronic control unit.