Working with Bodies
In 3D-CAD, a body is a single object, formed from a series of operations and features.
You can have two types of bodies: solid
or sheet (zero-thickness). Bodies that you create and import in 3D-CAD, and have a
hierarchy, are stored under the

node in the 3D-CAD model tree.
Bodies that have no hierarchy are imported as a flat structure. See Importing Geometry into 3D-CAD Model.
When you begin modeling in 3D-CAD, you create bodies from sketches, or by importing geometry. By default, imported geometry from external software packages is organized in groups, called body groups, and the structure/hierarchy of the geometry model is maintained. You can switch to a flat list view of all bodies. See Controlling how Bodies are Organized in the 3D-CAD Tree.