When you make a Spotify playlist private, it means that only you can access and listen to this playlist. It will not appear in public searches, nor can it be seen or accessed by your followers. This is a great option if you have a playlist that you'd rather keep to yourself. To make a playlist private, you simply right-click on the playlist and select 'Make Secret'. Remember, you can always change it back to public if you decide to share it with others in the future.