A system image is a complete backup of your computer's operating system, software, and settings. It includes everything needed to restore your computer to its current state in case of any issues or problems that may arise. A system image can be created using various tools such as the built-in Windows Backup tool, third-party imaging software, or by creating a disk image on an external drive. This type of backup is particularly useful for restoring your computer to its original state after a malware infection, hardware failure, or other issues that may prevent the system from booting properly.