(usually by holding Volume buttons while plugging in the USB) to perform the firmware write.

The tool communicates with the device via USB, typically requiring the device to be powered off and using the "Download Agent" (DA) file to initiate the handshake. While powerful, the official version has limitations, such as vendor-specific authentication (e.g., SLA/DAA for newer devices), the inability to bypass certain lock mechanisms, and restricted partition r/w access on secured devices.