Which of the following is not a graphics file format?

A graphics file format is a file format used to store image data - pixel colour values (raster) or path/shape data (vector) - so that visual content can be displayed or edited.

Checking each option against this definition: GIF, JPG, and PNG are all raster image file formats that store picture data, so all three qualify as graphics formats. WAV instead stores digitized sound-wave samples (PCM audio data) - it carries no pixel information at all, so it is not a graphics format.

• GIF (Graphics Interchange Format) - stores raster images and simple animations using LZW compression.

• JPG (JPEG) - a compressed raster format used for photographs.

• PNG (Portable Network Graphics) - a lossless raster format that supports transparency.

• WAV (Waveform Audio File Format) - stores digitized audio samples; it is an audio format, not a graphics format.

Since WAV is the only format among the four that stores sound rather than images, it is the one that is not a graphics file format.