Linux is pretty fast, but thanks to the Grub boot loader, it can take quite a lot of time for everything to start up and become usable. Therefore, if you want to speed up the boot of your Linux system, it is critical that you modify the default startup setting in the Grub bootloader so that your Linux boot speed isn’t too slow. More info https://www.addictivetips.com/ubuntu-linux-tips/improve-linux-boot-speed-grub-tweak/