Its the Blur effect.It can be done in Photoshop also.
TO do that follow these steps.Its simple.
1) Open the image.
2) Select the particular part or the entire image which u need to blur.
3) Go to filter menu and select any kind of blur(i.e., Guassian blur,Motin Blur,etc)
4) The angle and ratio selection window will appear with a zoomed preview.Adjust it based on your necessity.