---
title: CBDescriptor
framework: corebluetooth
role: symbol
role_heading: Class
path: corebluetooth/cbdescriptor
---

# CBDescriptor

An object that provides further information about a remote peripheral’s characteristic.

## Declaration

```swift
class CBDescriptor
```

## Overview

Overview CBDescriptor and its subclass CBMutableDescriptor represent a descriptor of a peripheral’s characteristic. In partcular, CBDescriptor objects represent the descriptors of a remote peripheral’s characteristic. Descriptors provide further information about a characteristic’s value. For example, they may describe the value in human-readable form and describe how to format the value for presentation purposes. Characteristic descriptors also indicate whether a characteristic’s value indicates or notifies a client (a central) when the value of the characteristic changes. CBUUID details six predefined descriptors and their corresponding value types. CBDescriptor lists the predefined descriptors and the CBUUID constants that represent them.  |   |   |   |   |   |   |

## Topics

### Identifying a Descriptor

- [characteristic](corebluetooth/cbdescriptor/characteristic.md)

### Accessing Descriptor Data

- [value](corebluetooth/cbdescriptor/value.md)

## Relationships

### Inherits From

- [CBAttribute](corebluetooth/cbattribute.md)

### Inherited By

- [CBMutableDescriptor](corebluetooth/cbmutabledescriptor.md)

### Conforms To

- [CVarArg](swift/cvararg.md)
- [CustomDebugStringConvertible](swift/customdebugstringconvertible.md)
- [CustomStringConvertible](swift/customstringconvertible.md)
- [Equatable](swift/equatable.md)
- [Hashable](swift/hashable.md)
- [NSObjectProtocol](objectivec/nsobjectprotocol.md)

## See Also

### Services

- [CBService](corebluetooth/cbservice.md)
- [CBMutableService](corebluetooth/cbmutableservice.md)
- [CBCharacteristic](corebluetooth/cbcharacteristic.md)
- [CBMutableCharacteristic](corebluetooth/cbmutablecharacteristic.md)
- [CBMutableDescriptor](corebluetooth/cbmutabledescriptor.md)