Grub is a boot loader for many Linux distributions which basically tells your system where it can find installed operating system(s) on one or more hard drives. Your PC needs this information in order to boot into your Linux distro successfully. If grub becomes corrupted, one such error you may come across is "error: no such partition grub rescue."
This is a companion discussion topic for the original entry at https://linuxconfig.org/how-to-fix-grub-error-no-such-partition-grub-rescue