The major difference between the night vision and the thermal imaging system is that the night vision is usually made for better identification and the thermal imaging is well known for the detection process.
The thermal imaging helps to detect the radiation or heat formation whereas, the night vision images provide a natural and detailed outlook. The night vision requires infrared light to perform the operations whereas, the thermal imaging does not require any visible light on the targeted image.
The night vision depends mainly on the light source whereas, the thermal optics does not depend on any ambient light source. The thermal imaging devices constitute the ability to work both in the day and night light whereas the night vision devices possess the capacity to work only in daylight.