On Spline, all objects "live" in a 3D space, but we consider 2D objects the ones with
Height (but no
Depth), which means that they can only resize in the X and Y axes.
2D objects are useful when building User Interfaces. While they don't have a depth by default, you can still extrude these objects to give them volume.
Also, 2D objects can still be moved and rotated in the 3D space on all three axes (X, Y, and Z).
👉 Next Steps
Learn how to convert 2D to 3D.