DVD/Video Glossary
DVD: DVD stands for Digital Versatile Disc. It is very often used as a replacement acronym for DVD-Video, which is one standard based on DVD format.
VOB: VOB stands for DVD Video Object. It is basically one of the core files found on DVD-Video discs and contains the actual movie data.
BUP: BUP files found on DVD-Video discs are simply backup copies of IFO files and are only needed if the original IFO on disc gets corrupted.
IFO: In video editing, IFO normally refers to a file on DVD-Video disc and stands for InFOrmation. While the main content of DVD-Video disc are the VOB files which contain the actual MPEG-2 audio, video and subtitle streams, the IFO files provide information for DVD player where DVD-Video disc's chapters start, where certain audio tracks are located, etc..
MP4: MP4 is the official multimedia container for MPEG-4 video and audio. Although such video can be stored in a number of modern containers, including MPEG-2 PS/TS and Matroska, the development of MP4 is important because it gives hobbyists a replacement for the outdated AVI container which became the standard for MPEG-4 ASP (DivX, XviD, 3IVX, etc,...) video.
AVI: AVI, which stands for Audio Video Interleave, is a Container format used by Microsoft's Video for Windows multimedia framework. Since it was developed for Windows 3.1 in 1992 it lacks some features found in newer containers like MPEG or MP4, but is still widely used by consumers and even supported by some standalone DVD players. Although still supported in Windows, and suitable for certain formats like DV, it's not a good general purpose container, and even Microsoft uses other containers for their own video formats.
DVD5: DVD-5 is an acronym that means a DVD disc that is one-sided single-layer disc and can contain upto 4.38 gigabytes of data on it.
DVD9: One form of DVD discs that means a single-sided dual-layer DVD disc. DVD-9 can hold approximately 7.95 gigabytes of data, even though marketers like to use the 8.5GB value instead, but this is misleading and is calculated by using so-called "Japanese gigabytes" which means that gigabyte is calculated as 1,000 megabytes, but in real computer terminology, gigabyte is 1,024 megabytes.
DVD10: DVD-10 means a two-sided DVD disc that hold single data layer on both sides. Effectively this means that DVD-10 is a dual-sided DVD-5 and can hold 8.75 gigabytes of data with 4.38 gigabytes on each side. Two-sided discs need to be flipped over in order to access the other data side.
DVD14: DVD-14 is an oddball format that doesn't really exist anymore, but was used for a short period of time back in late 1990s and in early years of new millennium when manufacturing of DVD-18 discs was complicated and expensive. DVD-14 is a two-sided DVD disc that has one side which contains single layer of data and one side which contains two layers of data. In easier terms, the other side of the disc is DVD-5 and the other side of the disc is DVD-9. DVD-14 disc can hold upto 12.33 gigabytes of data.
DVD18: DVD-18 in an acronym that means a two-sided DVD disc with two layers of data on both sides of the disc -- in other terms, it is a two-sided disc that holds DVD-9 disc on both sides of it. DVD-18 disc can contain upto 15.9 gigabytes of data on it (with 7.95 gigabytes on each side).
Framerate: a.k.a frame frequency, is the measurement of the frequency (rate) at which an imaging device produces unique consecutive images called frames. It is also expressed in frames per second (FPS) and in progressive-scan monitors as hertz (Hz).
