QEMU (Quick Emulator) is an open-source machine emulator and virtualizer. It allows users to run virtual machines (VMs) on various hardware architectures, making it a valuable tool for cybersecurity professionals and developers. QEMU can emulate a full system, including processors and peripherals, enabling the testing and analysis of software in isolated environments. This is particularly useful for analyzing malware, testing operating systems, and developing low-level software like firmware or UEFI modules without risking the host system. QEMU supports hardware acceleration and can be integrated with other virtualization tools, such as KVM, for enhanced performance.