Starting with iOS 11, iPhones store photos in HEIC format by default. HEIC — High Efficiency Image Format — is highly efficient: it creates photos with about 50 percent less storage of comparable JPEGs while keeping great image quality. However there is a significant catch. HEIC is an Apple-specific file type which is not broadly compatible

Have you ever downloaded an picture from the online and noticed it saved with a .jfif file extension rather than the usual .jpg, this is common. JFIF — short for JPEG File Interchange Format — is a specification that defines how JPEG image data is encoded. Essentially, a JFIF photo is a JPEG file. The .jfif suffix appears mostly while saving