DVD stands for Digital Versatile/Video Disc. Normally a DVD stores its audio and video in MPEG-2 format. A DVD player or a computer equipped with a DVD-ROM is required to play DVDs.
DVD has gained tremendous popularity with its high-quality video and high storage capability. A recordable DVD stores up to 2 hours of very good quality DVD-Video, including several audio tracks. The movies on DVD have a 200% sharper picture and far better sound quality than VCDs.
It is also possible to have up to 4.37 GB ordinary data or mix DVD-Video and data on a recordable DVD that can be played by most computer DVD-ROMs.
DVDs can be classified into DVD-R/DVD-RW and DVD+R/DVD+RW and DVD-RAM according to their DVD Recording standards. DVD-R/DVD-RW and DVD+R/DVD+RW have pretty similar features and are compatible with many standalone DVD Players and most DVD-ROMs while DVD-RAM has less DVD Player and DVD-ROM compatibility but better recording features.
There are basically 4 different DVD Sizes. DVD-5 holds 4.37 computer GB, DVD+R/DVD+RW and DVD-R/DVD-RW supports this format. Also called Single Sided Single Layered. This is the most common DVD Media, often called 4.7 GB Media.
DVD-9 holds around 7.95 computer GB, DVD+R supports this format. Also called Single Sided Dual Layered. This media is called DVD-R9, DVD-R DL, DVD+R9, DVD+R DL or 8.5 GB Media.
DVD-10 holds around 8.75 computer GB. VD+R/DVD+RW and DVD-R/DVD-RW supports this format. Also called Double Sided Single Layered.
DVD-18, holds up to 15.9 GB. DVD+R supports this format. Also called Double Sided Dual Layered.