The Blur tool is a tool of many uses, it can be used to completely blur and render out of focus on a background. You can select both the opacity and brush size. To make the brush smaller or larger use the square bracket keys on your keyboard, they are just to the right of the letter P on your keyboard.
Now, here’s another use, if you have a portrait of someone and you would like to soften it and perhaps get rid of a few small lines, then this is the tool for you, check it out.
