Fourth-generation optical discs are a type of optical disc that was developed in the early 2000s. These discs are similar to DVDs and Blu-ray discs, but have a higher storage capacity. They are often used for storing high-definition video and other large files.
Some of the emerging trends in Fourth-Generation Optical Discs include the use of high-density discs, the use of multilayer discs, and the use of write-once discs.