Difference between bump map and displacement map in Maya: Maya Tutorials

Difference between bump map and displacement map in Maya:

Bump and displacement map allow to create surfaces that are not completely smooth. Go ahead and create a simple sphere and apply the Blinn material on the sphere. In the attribute of Blinn material, go to blinn1 and under this there is an option Common Material Attributes. Just scroll down and there is Bump Mapping option.
Take a look at the image

Image 2
bump-map-and-displacement 01

At the end of the Bump Mapping option there is a small checker box, click on that. It will open “Create Render note” window.
Image 3

Take cloth texture from there

Image 4
Cloth texture is attached to 2D bump map node. We can use this as a bump map node. Like that
Image 5
Adjust the Bump Depth and render

Image 6
The problem is that Bump map can not deform the surface or geometry. If you render it close up then you can understand. It creates a fake depth on geometry. And it is also a rendering tips. The edge of the sphere is smooth. It looks like bumpy but actually it is not. Like that
Image 7
So we can use now Displacement Map
Again use blinn material on this sphere
But if you look at the window there is not any displacement window in the Attributor editor to add the displacement map.
Where we actually have to add this? Please take a look at the image below
Image 8
Image 9
Displacement is applied as material not a as texture. 
Now render and see the difference.

Image 10
Displacement map changes the shape of the geometry.
A lot of people use displacement map on the ground plane to look like bumpy and rocky but one thing remember that displacement map changes the geometry. In displacement map you can get the shadow effect according to your geometry. Look at the image
Image 11
But in the bump map you can not get a shadow effect. Because of bump map cannot change the geometry. It creates the fake bumpy illusion and it is a render tips.
Image 12