You can convert a JFIF file to JPG, though the two formats are nearly identical, and most software will open a JFIF file as a JPG. On a Mac, you need to rename the JFIF file extensions to JPG and then ...

You take a photo on your iPhone and email it to yourself. You try to open it on your Windows laptop, but the computer says it cannot display the file. You see a file extension you do not recognize: ...