Translations:Handbook:AMD64/Blocks/Booting/5/en

At the boot prompt, users get the option of displaying the available kernels and boot options. If no choice is made within 15 seconds (either displaying information or using a kernel) then the installation media will fall back to booting from disk. This allows installations to reboot and try out their installed environment without the need to remove the CD from the tray (something well appreciated for remote installations).