Monochrome sensors have no Bayer mask, so every pixel records every photon at full resolution and efficiency; you capture through external R/G/B or narrowband filters and combine channels in processing — maximum quality and flexibility (essential for serious narrowband), but more gear (filter wheel) and more time. One-shot-color (OSC) captures all colors at once via the Bayer mask — far simpler and faster per target, ideal for limited clear nights and broadband or dual-narrowband work, at some cost in resolution/sensitivity. Choose OSC for simplicity, mono for ultimate control.