Difference between CD, DVD, and Blu-ray discs
Storage capacity. CD storage capacity of 750MB. Single-layer disc has a storage capacity of 4.5GB while a double layer has 9GB. Single-layer Blu-ray disc has 25GB while a double layer has 50GB. Types of laser light used. It uses red laser light to read and write data. DVD uses red laser light to read and write data to the disc.