Messages can be used to transport arbitrary data between applications of a solution.
Messages provide the possibility to send something to or from a thing using an arbitrary subject/topic. They contain a custom payload with a custom content-type, so you can choose what content fits your solution.
Example: From an application perspective, a message can be sent to a Thing or one of its Features to call e.g. an operation at a device.
Messages do not affect the state of a thing entity or a device. Therefore, Bosch IoT Things does not handle messages like commands: there are no responses which are produced by our service and no events which are emitted for messages. Instead, the message needs to be handled respectively by your solution.
See Claiming for an example of a special message type, dedicated to claiming ownership on a device.
See https://www.eclipse.org/ditto/httpapi-messages.html for examples of messages to and from things and their features.
In case you search for notifications reporting changes at a thing entity, try our Events section.