To select objects

• Click the object.
• Drag right to left for a crossing selection.
  
• Drag left to right for a window selection.
  
• When multiple objects can be selected, press Enter when you are done selecting.

To select sub-object parts with a mouse

For many commands, you can select sub-parts of objects or specified object types to allow you to restrict selection in a tight area.

• Command ⌘ + Shift + Left mouse click, window, or crossing.

Examples include:

• Curve and surface control points
• Polysurface and extrusion faces and edge curves
• Surface edge curves
• Mesh vertices, faces, boundaries, and edges
• Objects within a group