Learn how to find Particles board Device ID which uniquely identifies your Particle device (Boron, Photon, Electron) to the Particle cloud. It consists of 24 hexadecimal characters, and you should probably avoid sharing your device IDs in public.

A Device ID for a Particle boards are a unique combinations of numbers that identifies a Particle board. Its like a finger print for a human.
The Device ID can be used in varous aspects of the device life including claiming it when you initially get it. So do keep your Device ID a secret.