Chromecast audio, as the name says is the audio specific version of Chromecast. It does not have the functionality of video streaming. However, it is not inferior to Chromecast. It can do a lot of things which Chromecast cannot do.
Chromecast supports a 2.1 channel or a 5.1 channel Dolby sound, Chromecast audio supports all levels of audio. From a simple mono speaker to stereo, theatre, Dolby, beats, ATMOS and high end 24 bit DAC FLAC lossless audio. Chromecast audio has been made into an audio specific device and these features are not present in Chromecast as of now.
It also has its range of apps that support it. All premium music apps like Spotify and Pandora support it. Audio from YouTube can also be played on it. When it comes to pricing, this device is dirt cheap. It comes at a price of $25. At this price point users have started to buy multiple Chromecast audios and have connected them across all their rooms in different speakers.
Chromecast audio and Playlist:
Chromecast audio has made even older speakers relevant. If you have a speaker, just plug it into Chromecast audio and use it like a smart speaker now. As users have started to buy multiple Chromecast audio, google has done something which is again, not present in Chromecast.
Self-awareness has been introduced in Chromecast audio. A self-aware Chromecast audio will know if other Chromecast audios are on the same Wi-Fi network. This is not limited to awareness. Google has added another functionality. Just open cast app, checkbox those chrome casts on which you want to stream given that all of them are on same network and you can play music in synchronisation in all of your rooms using chrome casts.
Normally this setup takes a full music system arrangements, the wires and the wireless setup and making sure that all of them are connected in same topology. It used to cost a fortune as it was brand specific and if a single speaker got useless then many times users had to buy multiple new speaker. Chromecast audio has given a cheap and hassle free way to do so ourselves.
Playlist in Chromecast is not an issue. As multiple devices can control it, if a video from YouTube is playing and another user wants to play a video from Vimeo, he can add it to the queue and next video will automatically play from queue. Basically Chromecast playlist is app independent and user independent.
There were many queries to understand and ask of Chromecast audio had any first party service like this. Users are demanding that app independent queuing facility should be given to Chromecast audio users.
This might take some time. Chromecast apps can do it because extensive code has been written for them to do so. Almost all, but not every app can do so on Chromecast. On Chromecast audio, same functionality has not been implemented yet. Well not yet on first party basis.
However, users cannot directly open app, hit play and add it to the queue, there is a work around to do so. There is an app for Chromecast audio called Qcast music app. This app is available for android and iOS.
Users who have installed this app can open any app say YouTube Pandora or Spotify and then cast music from them to Chromecast using Qcast. Qcast gives a homogenous workaround to do so which has not been done on first party levels till now.
However, every user must have Qcast app installed in their devices to do so and should have at least a 2.4GHZ Wi-Fi support to do so. There is also a web version of this app in works to do the same thing without downloading the app.