Relations are used extensively in Solidworks. It is one of the most important features that allow for the creation of more detailed models. This article gives a brief overview on how to use relations in Solidworks.
Solidworks relations are used primarily to represent connections between surfaces, edges, faces, vertices, and bodies. They can be used to create much more complex designs by building relationships between various components and layers within a single model.
When you create a new object in Solidworks, two types of relations can be created: edge and surface (or face) relationships that help reinforce the overall structure and shape of the object as it is built up layer-by-layer; and vertex relationships that establish connections between surfaces within the same part or among different parts.