Viewport selection: locking can ensure that only the intended object is manipulated in complex scenes or in scenes where an object is surrounded or obstructed.
Using Lock and Unlock
The lock/unlock implementation in the Desktop Editor displays a lock icon in the hierarchy beside an object that is locked. This icon can be clicked to unlock the object.
If you hover over an object that is unlocked, an unlock icon will appear that can be clicked to lock the object.
When an object is “locked,” a user will not be able to move it using the manipulators or select it in the scene.
In order to change properties from the property panel, the user must select the object from the hierarchy.