MiniDVD

MiniDVD (also Mini DVD or miniDVD) is a DVD disc which is in diameter. Most MiniDVDs hold 1.4 GB of data, but there are variants that hold up to 5.2 GB. The MiniDVD is also known as a "3 inch DVD", referring to its approximate diameter in inches.
The 8 cm optical disc format was originally used for music CD singles, hence the commonly used names CD single and miniCD. Similarly, the manufactured 8 cm DVDs were originally used for music videos and as such became known as DVD single.
MiniDVD capacities.
Recordable 8 cm discs are commonly used in DVD-based camcorders. The most common MiniDVDs hold 1.4 GB of data, but there are variants that can offer up to 5.2 GB of storage space, through a combination of dual layers and sides. Mini DVDs are also available in +R, +R DS, +R DL, +R DL DS, +RW, +RW DS, -R, -R DS, -R DL, -R DL DS, -RW, and -RW DS variants, just like their full sized counterparts. (DL=Double Layer, DS=Double Sided)
Variants of MiniDVD.
Nintendo used a disc-based format for their GameCube system, which is a variant of an 8 cm DVD. This format is also supported by the pre-RVL-101 models on the Wii for backward compatibility with the GameCube.