Start streaming immediately by clicking on a playable item (track, album, year, favorite list etc.) or use the queue
as an intermediate placeholder for tracks about to be played. Read more
What's the difference betweeen "Put it in the queue" and "Play it immediately" ?
"When a track is selected" controls what happens when you click on a track name.
This personal setting can have one of two settings, as follows:
Put it in the queue: When selected, tracks will be placed in an intermediate list known as the queue.
Furthermore, you'll see a "Queue all tracks..." link next to performers, albums etc.
The contents of the queue may at a later step be streamed and/or transferred to one or more favorite lists.
Play it immediately: When selected, a given track will be streamed/played right after you click on it.