[1] The basic features of a portable CD player are: The play/pause button allows the user to pause in the middle of a track (song) and resume play where the listener left off by pressing the button again.
The liquid crystal display provides a visual indicator of remaining battery life, currently playing track number, and the amount of time elapsed on the track.
While audio typically is output via a headphone connector, higher-end models may feature an additional integrated speaker.
Some portable CD players feature an externally attached playback controller as depicted, to facilitate control while the main unit is placed in a bag or pocket.
For some users of CD-Rs, the solution to this is to burn the CD at a slower speed or use a different brand of recordable CDs.