The audio event is the box in the project on an audio track.
In Cubase it works like this:
On the hard drive is an audio file. If such a file gets imported it will land in the Pool (Cubase’s audio and video media asset manager) as an audio clip.
This step is taken as a clip can consist of multiple audio files. Why would it do that? In short - in order to allow non-destructive editing that would otherwise be destructive.
If a clip is put into the project it is actually an audio event. An audio event is like a window to the clip. It can be either the entire clip or just an excerpt of it (e.g. show the clip from sample 2300 until sample 45918).
So, in the project view you see only audio events, never clips nor files. An event refers always to exactly one clip. A clip refers to one or multiple audio files.
Wait… I made a graphic at some point: