A characteristic contains a value, properties, and configuration information. Characteristic is the combination of characteristic properties, characteristic declaration, characteristic value, and a descriptor. Characteristic properties define the level of access that characteristic grants. For example, if a characteristic is read-only it will be defined in the properties. The characteristic declaration can be seen as a characteristic overview where the name, description, type and the requirements of the characteristic is mentioned. Descriptors are used to define a characteristic value.
The following diagram shows a view of the BLE characteristics:
Heart Rate Measurement characteristic with overview, properties, security and ...
