Yep, the 'unit' is size in which one chooses to use. The exact same thing happens when trying to discuss micro services v monolith. Really it all comes down to

Yep, the 'unit' is size in which one chooses to use. The exact same thing happens when trying to discuss micro services v monolith. Really it all comes down to agreeing to what terms mean within the context of a conversation. Unit, functional, and end-to-end are all weasel words, unless defined concretely, and should raise an eyebrow when someone uses them.