What is the key distinction between a part and an assembly in SolidWorks?

A part in SolidWorks represents a single 3D object, which can be either a simple geometric shape or a complex design comprising features like extrusions, cuts, and fillets. This single entity is often used to define individual components that may later serve as building blocks for more complex designs.

An assembly, in contrast, is formed when multiple parts are combined together to create a comprehensive model that reflects how these components interact with one another. This interaction is crucial in representing real-world applications where individual components must work in unison.

The distinction highlights the structural hierarchy in SolidWorks, where parts serve as the fundamental building blocks, and assemblies depict the relationships and configurations of these parts when they are incorporated into a larger system. This understanding is pivotal for effective solid modeling and design.