Some Sony portable CD players are called a CD Walkman. Other vendors just call them portable or personal CD players. Some players run on conventional AA, AAA or rechargeable batteries, giving you anywhere between 10 to 28 hours of continuous play. If your portable CD comes with a special lithium battery or some other kind, it's a good idea to see how long each lasts and if replacing them may be too costly. So if you're at home and want to use your player, you'll be able to plug it into a socket, and save the battery life for when you're on the move.
Most CD players do have some kind of bass enhancer.
It refers to a volume control feature on portable CDs and stereos. AVLS manages the audio signal and automatically brings it down if it rises above normal, or brings it back up to level if audio becomes too low. One of the more common modes is Repeat Play, which allows you to play a song or an entire CD over and over until you tell it to stop. For all those times you were listening to a CD and stopped it, not remembering where you left off, the Resume mode comes to the rescue. The Intro Scan mode helps when you don't have a list of songs to refer to your music.