Figure 1.16 - Outline in multiple objects

From that outline, you will also notice that your last selected object has a

brighter color for the outline. In Blender, you have something called an

active object. That will be the last object you add to a selection.

Having control over your active object in a selection using multiple

objects is important sometimes because you need to use that active

object. For instance, in animation projects, you can create parenting

relations to objects. When you create a parenting relation between

objects, your active object will always be the dominant object.

It is possible to make any object from a selection to become active. After

selecting multiple objects, hold the SHIFT key, and click at any of the

selected objects. That object will become active.

How to remove an object from a selection? You must hold the SHIFT key

and double-click at any object. The first click makes the object active,

and the second removes it from the selection. If you are trying to remove

the active object from selection, one click will be enough.

Here is a summary of your selection shortcuts:

SHIFT+Left-Click: Add objects to the selection

SHIFT+Left-Click (with selected objects): Turn the object active

in the selection

SHIFT+Left-Click (In the active object): Remove it from the

selection

SHIFT+Left-Click twice (Any object but the active): Remove an

object from the selection