Hello. Blu-ray or Blu-ray Disc (BD for short) uses blue laser with short wavelength (405 nm) to read and write data, hence its name. However, the traditional DVD requires the optical head to emit red laser (wavelength is 650nm) to read or write data. Generally speaking, the shorter the wavelength, the more information can be recorded or read per unit area. The biggest advantage of Blu-ray movies is that the huge storage capacity allows us to store more data. The following is detailed information, hoping to help you. /view/74247.htm