What type of memory is used by blue ray disc?

Blu-ray discs use optical memory, which stores data in the form of pits and lands on the disc's surface. A laser reads these variations to retrieve the stored information. This technology allows for higher data density compared to traditional DVDs, enabling Blu-ray discs to hold significantly more data, typically up to 25 GB for single-layer and 50 GB for dual-layer discs.