The phrase "bootloader unlock" refers to the process of modifying or removing restrictions on a device's bootloader, which is the software that initializes and loads the operating system during startup. Full definition
Asus has released bootloader unlock tool for its Transformer Pad Infinity TF700T tablet that makes it possible to install custom recovery utilities on your device. (gadgetian.com)
- No U.S. availability - Lack of U.S. 4G LTE support - Low - light camera performance is sub-par - MIUI is still missing features found in stock Android - Bootloader unlocking process is unwieldy (androidauthority.com)
The Pixel 2 had its fair share of issues too, however, and the oddest is the disabled bootloader unlock option. (techtimes.com)