Different station types include different options.
...
This station type can broadcast by playing the content uploaded within its library (which is called “playlist”) or by relaying another stream. Compared to the “streaming only” station, this station type has the added “Playlist” feature and lacks the Master link credentials. Having no Master link credentials means that a broadcasting tool cannot connect to the stream. The “Playlist” can be used to upload audio content, that will take over automatically when another source is not being relayed. This guarantees your station has audio content streaming 24x7. In Loop Channel stations, a user can also adjust the Output media format and bit rate in settings>advanced, as in Streaming only stations this can be done through the encoder.
(How many songs and GB can the playlist withstand?)
...
Relay Stations
A relay station is basically a “copy” of the main stream.
Different uses apply for relay stations, for example you could track the audience of your station in different directories, devices or platforms.
You can easily create one through the “Stream URL’s” section of your station
...