# Device A device can be an MCU-based hardware (e.g. NodeMCU, Arduino, Raspberry Pi, etc), a finished physical product like a Smart Air Conditioner, or a virtual service that sends data to Blynk.Cloud using REST API. ## AuthToken Every device on the Blynk platform has an AuthToken – a unique identifier generated by Blynk.Cloud that is used to authenticate, validate, and connect devices to Blynk.Cloud. You can find it in the Device Info section of the required device: ![Authtoken](https://user-images.githubusercontent.com/72824404/120668495-300a0180-c497-11eb-8858-9dbf413d787f.png) AuthToken is usually not exposed to the end users due to security reasons (for the same reason you should not display it for public view anywhere). ## Template Inheritance Every device inherits a [Device Template](/en/concepts/device-template.md). Make sure you understand this concept before you start building something on Blynk platform. ## Ownership A Device always belongs to an Organization and usually has an owner. In most common cases, it's a user who activated the device. However, ownership can be changed by transferring the device to a different user or Organization. Owner of the device could be found under the device name: ![Ownership](https://user-images.githubusercontent.com/72824404/119472965-5fac6180-bd53-11eb-8178-84492a46bc76.png) Click on the owner name will open the user profile in case you have enough permissions to view it. Device owner is used mostly for the permissions to restrict the devices access within the organization. ## Access Access to a particular device can be limited based on the user role and a set of permissions. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.blynk.io/en/concepts/device.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.