Q: My paper's status changed from "Editor invited" directly to "Under review." What does it mean?
I submitted a paper to an Elsevier Journal. After 5 days, the status changed to "Editor invited". And 11 days later, it changed to "Under review". Now, the stage is "With editor". Does it mean that my paper will be rejected, or could it have already passed from the editor in such a short time?
The status "Under review" appeared even before an Editor was assigned to your paper. This, in my opinion, is an indication that the status "Under review" refers to an internal review, not to the external peer review. I feel inclined to think this way because it is the duty of the Associate Editor to identify peer reviewers and send your paper for review.
Since the status changed directly from "Editor Invited" to "Under review," and there was no other status such as "Editor Assigned" or "With Editor" in between, it seems unlikely that your paper was sent out for peer review.
Possibly, once the journal office received the paper, invitations for an Associate Editor were sent out immediately. While waiting for the Associate Editor to accept the invitation, the paper was checked by editorial assistants to ensure that the basic journal guidelines were met. During this time, the status showed "Under review." Once the Associate Editor accepted the invitation, the status changed to "With Editor." The Associate Editor will now conduct the initial editorial screening and send out reviewer invitations if your paper clears this screening.