The UIF extension is used in files that store compressed CD and DVD images. Most often, this format is associated with the free MagicISO program, although a few other programs of this type also support such files. UIF are files used for backing up CDs and DVDs, but also for data exchange. User can encrypt UIF files and protect them with a password.

An important feature of the UIF format is the ability to make copies of multisession disks with it. The program supporting the UIF MagicISO format works in the Microsoft Windows operating system.