“behavioural model” & “structural model”

The phrases "behavioural model" and "structural model" are commonly used for what we'll call "high-level models" and "synthesizable models". In most cases, what people call structural code contains both structural and behavioural code. The technically correct definition of a structural model is an HDL program that contains only component instantiations and generate statements. Thus, even a program with c <= a AND b; is, strictly speaking, behavioural.