Depends on what "Generation" you're talking about!
When I started in MIDI,
"Step" write was literally that...
A certain number of "Button Clicks" would denote a measure - Say "4" for 1 measure to be simple...
If you wanted a bass line to play on beats 2 and 4, you would:
- Click a "Rest" button once for a rest (Beat 1)
- Then click and hold a "note" button and press a key on the keyboard at the same time... That would be your bass note on 2... (Beat 2)
- Then Click the "rest" button again... (Beat 3)
- Then again click and hold a "note" button and press a key on the keyboard at the same time for the bass note... (Beat 4)
Then you would go back and press the play button on the "Sequencer" and your notes would play as you 'recorded' them...
(OMG am I GLAD That MIDI sequencers have improved DRASTICALLY over the years!)...
"Realtime" write - Is starting your sequencer in "record" mode and playing "live" into the sequencer to record your notes in time with a click track...
Hope this helps...