Photoshop Blur filters: What they are and how to use them
Photoshop Blur filters are designed primarily for retouching images—to soften, haze, cloud, fuzz, or distort specific areas of a picture or the entire image. Backgrounds are often blurred out to accentuate the main subject of a photo, or to reduce clutter in the environment. Blur filters also collect, then fuse the colors in a selected area to create a specific effect such as motion.
Blur effects explained
When you select Filter > Blur, Photoshop displays a dropdown menu with 11 Blur effects. They are defined as follows (and grouped by similarity):
Average: Photoshop considers all the colors of a selected area, then calculates the average color of the combined hues, and fills the area with that color. Once the area is “averaged,” you can apply additional effects such as a soft gradient, a simple texture, or a modest pattern to create an uncluttered background that doesn’t “compete” with the main subject of the image.