HEIF stands for "High Efficiency Image File Format" and is an image format developed by the Motion Picture Experts Group (MPEG). HEIF is a container format for images that allows for higher compression compared to other image formats like JPEG or PNG without compromising image quality. It is based on the same principles as the H.265/HEVC video format and uses an advanced encoding technology called High Efficiency Image Coding (HEIC).

HEIF files can also store multiple images or image sequences, such as a Live Photo, in a single container. This makes it particularly suitable for mobile devices where storage space and transfer speed are limited. HEIF is supported by many modern devices and operating systems, including iOS, macOS, Android, and Windows.