Definition - What does Hi-MD mean?
Hi-MD refers to an enhanced form of MiniDisc for storing and playing of media. It is magneto-optical, whereby a laser is used for reading and a laser along with a magnet is used for writing Hi-MD format media. The Hi-MD format was developed form of a MiniDisc but is now considered obsolete, whereas the MiniDisc is still used in some areas.
Techopedia explains Hi-MD
Announced in January 2004 by Sony, Hi-MD quickly became a popular choice for storing and sharing media due to its increased storing capacity, and ability to save non-audio data such as documents and other files, longer playback and recording time available per disc, improved codecs, wider compatibility, and better PCM algorithm. Hi-MD has a data storage capacity of 1 GB, whereas a simple MiniDisc can store data up to 350 MB.
The media storing format's laser as well as magnetic reading writing capabilities ensured more reliable playback. Although intended to replace MiniDiscs, Hi-MD was discontinued by Sony in 2012.