Complex sentence: Each letter designates a particular section of the electromagnetic spectrum; most of these sections fall within the region spanning the near-ultraviolet (NUV), the visible and the majority of the near-infrared (NIR).
Split into simpler sentences: Each letter designates a particular section of the electromagnetic spectrum. Most of these sections fall within the region spanning the near-ultraviolet (NUV), the visible and the majority of the near-infrared (NIR).