Q: What does the status from "under review" to "in review" means?

Detailed Question -

Recently,I have submitted my paper to one of the Wiley Journals, the status first change to "article received" then "under review" then after 3days of submission to "in review"..

1 Answer to this question

There is not much difference between "Under review" and "In review." It depends on the journal; one journal may use "Under review" while the others may use" In review." But, both the status mean that either editors or peer reviewers are evaluating your paper. 

Let me explain this!

If the status shows "Under review," then your paper is sent to the peers to evaluate the article. Or the associate editor must have sent the manuscript to a team of new or other potential peer reviewers.

If the status shows "In review," then your paper is at the editor's desk, and they are evaluating if the manuscript adheres to the aim and scope of the journal and the content correlates with them. If everything goes well, the editor moves the paper to "Under review" status. 

So, your article should either be at the editor's desk or with the reviewers. Also, you can check the author guidelines of Wiley journals' to understand the process.