This mimetype is deprecated. You should still support it, but avoid using it to assign new mimetypes.
Instead, please use image/heic
The MIME subtype name may be 'heic' only if the file conforms to the requirements of the 'heic', 'heix', 'heim', or 'heis' brand, and contains at least one of those brands as a compatible brand. The MIME subtype name may be 'heif' only if the file conforms to the requirements of the 'mif1' brand, and contains that brand as a compatible brand.
HEIF (High Efficiency Image File Format) is the lossy image and animation format defined by MPEG-H Part 12 (ISO/IEC 23008-12).
It is closely related to the HEVC video format, so in that way it is similar to BPG. It uses boxes/atoms format as a container format, so in that way it is similar to JPEG 2000.
File types
.heic .heif