Fastboot mode is a mode of controlling the phone and operating system via command line and ADB interface. It is used to restore the phone after installing a failed update, changing hidden settings, flashing the device, factory reset, OEM unlocking, boot loader recovery, and other procedures. It allows the user to write data to the internal storage of Xiaomi, Mi, Redmi, and POCO phones without booting the entire system.

To enter Fastboot mode on a Redmi phone, you need to turn off the phone completely and then press the power and volume down buttons simultaneously. The image on the screen signaling to enter Fastboot mode may differ depending on the phone model. To exit Fastboot mode, you can try pressing the power button or the volume up/down button. If the phone is stuck in Fastboot mode, it may be due to a jammed volume button, and you may need to get it fixed.