The Mesh Parts () branch under Global Definitions has features to create a Mesh Part in 3D (), 2D (), and 1D (). The Mesh Parts node appear when you add a mesh part by right-clicking the Global Definitions node and choosing a mesh part from the Mesh Parts submenu.

A mesh part contains an imported mesh or meshing sequence and possibly additional meshing operations such as partitions. You can use a mesh part in a geometry sequences by referencing it in an Import node. Also, when importing a mesh using an Import node in a geometry sequence, a Mesh Part node is created.