Digital photography is saved in a form that is compatible with computers. This form is known as a file and there are several different kinds of file formats that cameras can use. In addition, there are many other picture formats that are used in digital imagery and on the Internet. Still image formats can usually be converted from one kind to another kind, if necessary. Information can be lost in the conversion, and in some cases a lot may be lost. While you probably are familiar with files and have worked with them, you may not know exactly what they are.

File names have a set format. Every one of your picture files has a name that either the camera automatically assigns or you give it. After the name comes a dot and then the file extension. While you can change the name, you should never change the extension. For example, a photo named Mypicture and saved in the JPEG file format looks like this: Mypicture.jpg.

The Windows Explorer file manager often hides file extensions. By default it does not show file extensions when it lists files in a folder. To change this and see your extensions listed, go to Tools > Folder Options > View and then uncheck the option that says Hide Extensions for Known File Types.