Gone are the days of the CD racks. They are now being replaced by iPods and other MP3 players that can put entire music libraries at the palm of your hand. It's like jumping into the world of digital music files where you can be free of all the space designated for CDs. You can take it wherever you like, listen to your library in the car, at the gym, at home and at work.

Digital Audio Players, more commonly referred to as MP3 players, are portable handheld electronic devices that store, organize and play audio files. Some DAPs are also referred as Portable media players, as they have image-viewing and video-playing support.

Today, MP3 players--available in a wide variety of styles and sizes and capable of storing thousands of songs--capitalize on digital technology to supplant traditional Walkman-style cassette-tape players and portable CD players. Whether you want to get your groove on while working out or would like to amuse yourself as you commute on public transit, a portable MP3 music player would suit your needs.

MP3 players use one of the two storage mediums: hard drives or flash memories. A hard-drive player offers the greatest amount of storage space but tends to be larger. Flash-memory models hold a more limited number of songs, but they are more durable than hard-drive players.

Nearly all MP3 players require a reasonably modern PC with a free USB 1.1 or 2.0 ports. Specialized MP3 players are not the only devices you can buy to listen to your music: You can now get mobile phones, thumb drives, digital cameras, personal digital assistants, and car stereos that can store and playback MP3 music files.