Firmware is a type of software that controls the functionality of a specific hardware device. In the case of AirPods Pro, the firmware is responsible for managing the audio playback, noise cancellation, and other features of the device. The current version of AirPods Pro firmware is 4A400, which was released on May 10, 2023.
Firmware updates for AirPods Pro are released regularly to improve the performance and stability of the device. These updates can include new features, bug fixes, and security enhancements. It is important to keep your AirPods Pro firmware up to date to ensure that you are getting the best possible experience from your device.