JPEG is a standard format for digital photography that uses so-called lossy compression. This means that when an image is saved, the data is reduced to make the resulting file smaller. This reduction is irreversible and may slightly reduce the quality of the image. Lower compression preserves more detail at the cost of a larger file, while higher compression produces smaller files, which is useful for saving space on the memory card but can lead to loss of fine detail. Settings can also include a choice of aspect ratio for the photo, such as 4:3, which matches the shape of the sensor, or 16:9 widescreen.
