DVD-5 discs are one-sided, single layer recordable DVDs with a capacity of 4.7GB. The numbering after DVDs can be approximated to the capacity of the discs. For example DVD-9 discs can hold 8.5GB on a one-sided, double layer disc and DVD-18 can hold 17.4GB on a dual-side, dual-layer disc.
DVD-5 discs are 12cm discs and can be created through the production processes of either DVD duplication or DVD replication. DVD-5 are the most common type of DVD as the 4.7GB capacity is currently more than enough for most applications or requirements, holding 120 minutes of high quality audio and video.
DVDs have much higher storage capacities than CDs by using smaller pit sizes and narrower track pitches in the spiral groove that runs around the discs. These smaller pits and grooves require a different wavelength of laser light (650nm) to that used in CD drives (780nm) and therefore DVD discs cannot be read in standard CD drives.