Have you noticed some pictures on i devices and in Windows 10
now have an extension of HEIF (High Efficiency Image File
Format), instead of JPG (Joint Photographic Experts Group)?
It is a new designation
for pictures and supports bonus features, such as it can
accommodate live photos, bursts of photos, 3D scene data useful
for special effects, audio, and more. As a container, HEIF can
actually accommodate multiple compression technologies. When
used with HEVC video compression, the resulting files are called
HEIC images.
It compresses the file size to roughly half the size of JPG
files to save space. The quality is reported to be identical.
Apple is using is also using it as a new standard, so you will
be seeing more of these picture file types. Incidentally, it is usually pronounced heef.