It is based on frame construction, but the main difference is that a modular house is built as a set of individual modules.
These modules are fully assembled in the factory, including electrical wiring, plumbing, interior and exterior finishes, and then delivered to site and installed within a day.
In terms of energy efficiency, quality, and living comfort, modular homes are no different from traditional frame homes.
When choosing between them, you should mainly focus on the layout and look that you like best.