Jpeg File Extension
Jpeg stands for Joint Photographic Experts Group image files. These file formats may be viewed by Photoshop,Acdsee or Irfan View softwares.
These extensions are used for saving the photo based files. Jpeg files show better quality and compression effect with the files which have upper than 256 colors.
It is better option that using GIF files with the images that have lower than 256 colors
You can view JPG images with any image viewer softwares.
What needed to Open Jpeg file extensions.
Photoshop, Acdsee, irfan View
Links about Jpeg file extension