Is the bounds.size and the GetComponent.BoxCollider2D.size of a GameObject meant to be the same?

I have a script attached to a GameObject with the following code:

Code (CSharp):

1. public class Player: MonoBehaviour{
2.  
3. private BoxCollider2D _col2D;
4.  
5. void Start(){
6.  
7.     _col2D = GetComponent<BoxCollider2D>();
8.  
9. }
10.  
11. void Update(){
12.  
13.  
14. Debug.Log("The size of the Bounding Box equals: " + _col2D.bounds.size);
15. Debug.Log("The size of the BoxCollider2D equals: " +_col2D.size);
16.  
17. }
18.  

I would have thought that "_col2D.bounds.size" and "_col2D.size" would output the exact same thing however when I run this code it outputs the following to the console:

Code (CSharp):

1. Size of Player's BoxCollider2D component is(5.2, 8.4)
2. Size of Player's Bounding Box is(1.6, 2.6, 0.0)

}

Could someone help me why the Vector values of these two things are different?