Beginner PM question

I don't have access to SAP quite yet (so I am obviously a complete newbie), so when I needed a report on all of the scheduled work orders for a production line, a coworker printed it out for me (image below). I am trying to organize it, but I am having issues with understanding what each column means, more specifically the dates:

What exactly does date created / date changed on mean? First I thought "created on" meant when the work order was scheduled, and "changed on" was the date it actually got carried out, but some of the dates are three years apart, so it doesnt really make any sense. This is probably super stupid & simple, but any serious answers (with any other helpful tips if you don't mind) are greatly appreciated!