Odin (firmware flashing software)
Odin is a utility software program developed and used by Samsung internally which is used to communicate with Samsung devices in Odin mode (also called download mode) through the thor protocol. It can be used to flash a custom recovery firmware image (as opposed to the stock recovery firmware image) to a Samsung Android device.
Source: Wikipedia — Odin (firmware flashing software) (CC BY-SA 4.0)