JPEG (short for Joint Photographic Experts Group) images can be used for saving graphics to use in web pages. They can have a ".jpg" or ".jpeg" extension.
JPEG images are commonly used for web page graphics because they are widely supported in web browsers and can have small file sizes. With those smaller sizes, though, comes some compression artifacts that can make your image less attractive. You can set the level of compression when saving a JPEG.
Note: JPEG images do not support transparency. Use PNG or GIF images if you want to use transparency in your image.