Secure Boot is a security standard designed to protect the computer's boot process from malicious software, such as rootkits and unauthorized operating systems. It works by allowing only software that is digitally signed and trusted by the Original Equipment Manufacturer (OEM) to run during the system's startup. When the PC powers on, the firmware (usually UEFI) checks the digital signatures of each piece of boot software, including firmware drivers, EFI applications, and the operating system itself. If any software lacks a valid signature, the firmware prevents it from running, thus blocking potentially harmful code from taking control of the system during boot. Secure Boot replaces the older BIOS boot process by adding a layer of cryptographic verification, ensuring that the bootloader and operating system have not been tampered with. It is commonly used in modern PCs, especially those certified to run Windows 8, 10, and 11, and is also supported by some Linux distributions through signed loaders. While Secure Boot significantly improves security by preventing unauthorized modifications during startup, it can sometimes be disabled or bypassed, which may undermine its protection. It is generally recommended to keep Secure Boot enabled for better system security and stability. In summary, Secure Boot enhances the safety of the PC boot process by verifying the authenticity of the boot software, protecting against rootkits and malware that try to load before the operating system starts. This feature is widely implemented in modern UEFI firmware and is an important part of the secure computing ecosystem. If you'd like, I can also provide guidance on how to check or enable Secure Boot on your system. Let me know if you want that or have other questions!