Here are some of the most important differences:
- MIDI defines a hardware interface (i.e., the MIDI cable), but OSC does not. OSC is typically transmitted over ethernet.
- MIDI uses a compact binary message format with a limited number of fields, e.g. channel, note, velocity, etc. OSC has a binary data section, but a human readable, URL-style address that looks like "/foo/bar".
- OSC allows one to transmit multiple data types commonly used on modern computers including 32-bit integers, floating point numbers, strings and more. MIDI only transmits integers.
- OSC includes a high-precision timestamp with picosecond-resolution that allows OSC messages to be scheduled, recorded and reproduced with minimal jitter. The MIDI beat-clock is a low-resolution clock having a precision on the order of several milliseconds at best.
For more information, see this poster: http://opensoundcontrol.org/files/OSC-Demo.pdf
The short answer is, use "Open Sound Control".
Back in the old days we had
OpenSound Control
OpenSound World
OpenSound (etc)
On occasion one may also encounter "Open SoundControl" and "OpenSoundControl". It's a bit of a mess. When Googling for OSC-related topics it may be necessary to check all of these forms.
