accepting and online first publish date Is there any difference between accepting date and First Online date? For example in the journal Acta Mathematicae Applicatae Sinica, English Series , I see this

Received, Revised, First Online 

03 April 2014, 17 February 2015, 04 October 2018

from

https://link.springer.com/article/10.1007/s10255-018-0786-2

and there is no information about accepting date. I would like to know what is the difference between them and when papers are accepted in this journal. 

the journal Applications of Mathematics only shows the  Received, First Online date and not the revised date.

thanks
Manuscripts are received, possibly revised (several times), maybe accepted, then online, and finally published (for non online-only venues), venues may show some or all of the dates of those events.