Click: Move the mouse pointer over an object and press and release a mouse button once.

Double-click: Move the mouse pointer over an object and press and release a mouse button twice fast.

Drag: Move the mouse pointer over an object and hold down a mouse button, then move the mouse with the button held down. Then release the mouse button.

Click-Drag: Move the mouse pointer over an object, press the mouse button, and move the mouse pointer to a final position before releasing the mouse button.

The Scene: The 3D “world” inside the view windows.

The Model: The curves, surfaces, and points that make up the object you are creating.