The difference between IOS bounds and frame

Write the case code today, find the data on the setting of a UIButton frame, this is set

Btncover.frame = Self.view.bounds;

But I wrote it the first way.

Btncover.frame = Self.view.frame;

Later, I found that two different ways to achieve I want to think about, that is, the size of UIButton and the size of the parent container is consistent, I wonder, since the same effect, why there are bounds and frame. Later, the following differences were found:

-(CGRect) frame{    return CGRectMake (Self.frame.origin.x,self.frame.origin.y,self.frame.size.width, Self.frame.size.height);}

-(CGRect) bounds{    return CGRectMake (0,0,self.frame.size.width,self.frame.size.height);}

, observing the above two code, found that the frame of the far point is arbitrary, and the origin of the bounds is 0, 0.

Frame: The position and size of the view in the parent view coordinate system. (reference point is, Father's coordinate system)
Bounds: The position and size of the view in the local coordinate system. (The reference point is that the local coordinate system is equivalent to VIEWB's own coordinate system, starting at 0, 0 points)

The difference between IOS bounds and frame