What triggers a document to appear as "edited"? What triggers a document to create a new version?

[Clinton Myers]

I need some clarity on what makes a document appear as "edited" across Office 365.

For example, in the Recommended section of the O365 landing page, there is a description of the document's status such as, "This document was edited...".

When users bring this up, I often hear, "I just opened and viewed the document. I did not make any changes." And while this is true (there is no new version in Version History), Office 365 shows it as "edited".

In general it seems that just viewing a document is enough for Office 365 to show the document as "edited", while more impactful changes are needed to trigger a new version.

Can you explain the triggers?

[#2]

Well, you can check if someone has edited or not a document in the Audit Log Search in the Security & Compliance Center so you can be sure if a document has or not edited by someone...remember that in Office 365 you have Autosave enabled so if someone makes a change in the document, the change is automatically saved