The document discusses x-ray machines and how they work. It explains that x-ray machines take electrical energy and convert it into two voltage streams: a low voltage that controls the filament current measured in mA, and a high voltage measured in kVp that produces x-rays. It states that increasing kVp produces x-rays with higher energy and shorter wavelength, while the mA controls the intensity of the x-ray beam by varying the current through the filament. The document also discusses how factors like kVp, mA, distance and filtration determine the quality and quantity of the resulting x-ray beam.