yeah that’s correct. the IN (button 1) is the start of a loop and the OUT (button 2) is the end and as long as you have button 3 clicked (loop symbol) that loop will continue to play.
Say your loop is a bar, to jump to the next bar use the shift and right arrow whilst playing the first. When it gets to the end of the first loop the markers and loop will then jump to the next bar to the right.
You make multiple loops along the timeline (tape) and jump back and forth between them.
There are loads of handy tutorials on YouTube made by some of the guys who hang about on here - they are a million times more helpful than someone trying to explain the OP-1 using text …