Add paragraph explaining audio-endpoint-codec vs codecs query difference

Author: AntonPo456

uwp/audio-video-camera/supported-play-type-strings.md

@@ -117,6 +117,8 @@ It is up to the content provider to choose the resolution limit to use when this
 
 Some audio playback scenarios require the audio endpoint to support the a given audio codec or feature natively. The *audio-endpoint-codec* extension is useful for applications and streaming services, allowing them to figure out dynamically whether they should send stereo audio or 5.1 (because the device supports 5.1), and therefore control used bandwidth while maximizing audio quality. It also exposes information on whether the audio endpoint is connected to a device that can decode the audio format in hardware instead of relying on the software decoder on the system.
 
+The `audio-endpoint-codec` query differs from the `codecs` query because it determines whether the audio endpoint device connected to the PC supports the specified format. So, for example, if a PC has the software decoder for the AC3 codec, the `codecs=ac-3` query will succeed. If the PC is using basic headphones as the audio endpoint, the `audio-endpoint-codec=ac-3` query will fail. But if the PC is connected to an audio/video receiver that can decode AC3 format, the `audio-endpoint-codec=ac-3` query will pass.
+
 Support for *audio-endpoint-codec* was introduced in Windows 10, build 1803.
 
 The following is an example content type string using *audio-endpoint-codec* checking for the audio endpoint hardware support for the Dolby Digital decoder.