JPEG is a compressed graphic format that supports up to 24-bit color therefore it is suitable for storing photographic images.
JPEG compression values can be modified so that a balance is reached between image quality and file size.
Due to this fact, users prefer to convert their files to JPEG in order to reduce size while still maintaining the original graphic quality.
There are numerous graphic applications that will allow users to adjust an image's size, colors or orientation before converting it to JPEG.
Another method to create JPEG files is to use image capture tools, then save the screenshot to JPEG format.