When you upload tracks to SoundCloud, you have two options for how you want to share them with other users: Public and Private. When uploading a playlist, you are choosing what privacy setting you would like the playlist to be, and this will also be the same for the tracks within the playlist
Differences between Public and Private Sharing
Public sharing means that anyone can listen to your playlist and tracks, and they will show up on your SoundCloud profile page and your followers’ Streams. Private sharing is exclusive, giving you control over who has access to your playlist and the tracks within it. Private playlists and tracks won't show up on your public profile and can't be searched for within SoundCloud.
How to change your privacy settings
To change the sharing settings of your playlist, click on the bubble next to the word ‘private' or 'public' and click save.