Explain the difference between behavioral and structural modeling in HDL.

Behavioral modeling in HDL describes the functionality of a digital system using high-level constructs without specifying the detailed implementation. It focuses on what the system does rather than how it is constructed. Structural modeling, on the other hand, describes the system in terms of its components and their interconnections, detailing the actual hardware implementation. Behavioral modeling is used for initial design and verification, while structural modeling provides a detailed and accurate representation for synthesis and implementation.