Beforemoving ontothe Redmi bootloader unlock tool with the unlocking process, we should know about the function of the bootloader.
The bootloader is a kind of code that runs prior to operating systems to start its operation. There are specific bootloaders on every smartphone.
Now, Xiaomi is using it to give the user better protection in terms of security. It blocks the user to bring any changes to the entire system.
For example, with a locked bootloader, you cannot flash the custom ROM. It will also block you from booting to stock recovery for factory data reset. It saves your data even if you have lost your device or it gets stolen by somebody.