Computer science background images

What is the use of background in computer?
A wallpaper or background (also known as a desktop background, desktop picture or desktop image on computers) is a digital image (photo, drawing etc.) used as a decorative background of a graphical user interface on the screen of a computer, smartphone or other electronic device..
Why is background image important?
Helps Users Focus on Core Design Elements
A simple background design helps users focus on the core design elements of your image, like a graphic, logo, or text.
After all, you want the focus to be on your call to action so they can act on it..
A computer image is a picture composed of an array of elements called pixels.

What is the use of background in computer?