An IMG file is a disk image, a single file containing the complete structure and contents of a data storage medium, such as a hard drive, floppy disk, CD-ROM, or DVD. It's essentially a sector-by-sector copy of the original disk. This makes it useful for creating backups of entire systems or individual drives, distributing software, and emulating older operating systems or hardware. IMG files can be mounted as virtual drives, allowing users to access the files and folders within the image as if they were on a physical disk. They are often used for creating bootable media, allowing users to install operating systems or run diagnostic tools from a USB drive or CD. The format is relatively simple and widely supported, making it a versatile option for disk imaging tasks. Different tools might use slightly different variations of the IMG format, but the core principle of a sector-by-sector copy remains the same. They are not typically compressed, so they can be quite large, reflecting the size of the original disk.