Without searching for the video, let's 'pretend' he was talking about the reality that the digital sensor captures at just 1 (one) ISO setting, the 'base' ISO for that model. This 'base' ISO is typically ISO-100, but some cameras it is ISO-200, or somewhere in this range. When you dial any other ISO value, the 'computer' that is the processor inside the digital camera will process the data from the digital sensor to achieve the specified ISO. And yes, those international standards are how each camera manufacturer determines the amount of 'gain' to add to the sensor data to achieve the specified and standardized ISO setting. The signal from the sensor is 'amplified' and it is this applied amplification to the data that is the source of most digital noise in the resulting image file. This is also why the best noise performance and widest Dynamic Range of the camera occurs at each digital camera's 'base ISO'.