What it is
The job it was built for, and the job it is not for.
Gemini Flash Latest is not a fixed model, it is a rolling pointer to whichever Gemini Flash model Google currently ships as newest. The job it does is keep an integration current, so a team building high-volume multimodal work on Flash inherits the latest version automatically. It is the wrong choice when you need a stable, pinned target whose behaviour will not shift under you, for example anything under evaluation, audit or regression testing.