DVDs come in two sizes: 4.7GB single-layer discs and 8.5GB double-layer discs. Single-layer DVDs are more common than double-layer DVDs, mostly due to how relatively inexpensive they are. Nevertheless, double-layer DVDs are used by many people for file backups and media burning. Windows supports burning DVDs in both the 4.7GB and 8.5GB size, so if you need to burn some larger personal files or an ISO image file larger than 4.7GB, use an 8.5GB double-layer DVD. Warnings Writer Bio
