Photo editing improves the quality of an existing photo or graphics image.
Here is a list of reasons for editing images:

• image is too light or too dark
• image is too big
• image needs touch ups, red eye removal
• image needs to be cropped (you want the face and not the whole picture)
• you want black and white, duotone or different colors from the original
  (useful for background image with text overlays)
• include special effects like feathering, shadowing, or embossing
• you want to remove or replace the background in the image
• image file is not optimized for web

View graphics design to learn what software may be used to create or edit graphics.