High-level design (HLD)
High-level design (HLD) focuses on the overall software architecture and structure of a system, while low-level design (LLD) – the more granular end of software design – provides detailed specifications for individual components.
HLD provides the "big picture" view, outlining major components and their interactions, while LLD defines the specific implementation details of each component.
Different modeling notations represent different levels of abstraction. The C4 model’s context and container levels correspond to the high-level view, while its component and code levels to the low-level view.