Here are a few examples of typical MIDI messages:

MIDI messages are extremely compact, due to the low bandwidth of the connection, and the need for real-time accuracy.

MIDI messages can often also be used to control parameters of both instrument and effect plugins.

They organize MIDI messages into one or more parallel tracks, and timestamp the events so that they can be played back in sequence.

MIDI messages are sent in only one direction, so a second cable is necessary for two-way communication.

MIDI messages are made up of 8-bit words, and are transmitted serially at a rate of 31.25 kbaud.

A MIDI message is an instruction that controls some aspect of the receiving device.

Further, patches can be imported and exported via system-exclusive (sysex) MIDI messages.

It just sends out the MIDI messages telling the other instruments what to play.

And computers are naturally equipped to handle and manipulate digital data like MIDI messages.