The MP3 player is the most recent in an evolution of music formats that have helped consumers enjoy their tunes. Records, 8-track tapes, cassette tapes and CDs — none of these earlier music formats provide the convenience and control that MP3 players deliver. With an MP3 player in hand or pocket, a consumer can create personalized music lists and carry thousands of songs wherever they go.

All of that stored music and the MP3 player itself fit into a device that, in some cases, weighs less than one ounce. Portability is a large factor in the popularity of the MP3, considering the ease of transportation in comparison to a CD player and CD storage case. In addition, some devices provide additional technology, like video and photo viewing, alarm and calendar functions, and even cell phone and Internet service.­
­In this article, you’ll learn more about the technology inside MP3 players and the diff­erent types of players available. You’ll also find out how to get tunes and how you can accessorize your player. Get started by learning about the MP3 file format on the next page.

The MP3 File Format

The MP3 file format revolutionized music distribution in the late 1990s, when file-swapping services and the first portable MP3 players made their debut. MP3, or MPEG Audio Layer III, is one method for compressing audio files. MPEG is the acronym for Moving Picture Experts Group, a group that has developed compression systems for video data, including that for DVD movies, HDTV broadcasts and digital satellite systems.
Using the MP3 compression system reduces the number of bytes in a song, while retaining sound that is near CD-quality. Anytime you compress a song, you will lose some of its quality, which is the trade-off for the ability to carry more music files in a smaller storage system. A smaller file size also allows the song to be downloaded from the Internet faster.
Consider that an average song is about four minutes long. On a CD, that song uses about 40 megabytes (MB), but uses only 4 MB if compressed through the MP3 format. On average, 64 MB of storage space equals an hour of music. A music listener who has an MP3 player with 1 GB (approximately 1,000 MB) of storage space can carry about 240 songs or the equivalent of about 20 CDs. Songs stored on traditional CDs are already decompressed, so it takes more CDs to store the same amount of songs. (Some CDs support MP3 files.)
Although MP3 is perhaps the most well-known file format, there are other file formats that can be played on MP3 players. While most MP3 players can support multiple formats, not all players support the same formats. Here are a few of the file formats that can be played on different players:

• WMA – Windows Media Audio
• WAV – Waveform Audio
• MIDI – Music Instrument Digital Interface.
• AAC – Advanced Audio Coding
• Ogg Vorbis – A free, open and un-patented music format
• ADPCM – Adaptive Differential Pulse Code Modulation
• ASF – Advanced Streaming Format
• VQF – Vector Quantization Format
• ATRAC – Sony’s Adaptive Transform Acoustic Coding 3

In the next section, we’ll look at the technology behind the player that allows you to listen to your music.

For more Detail: How MP3 Players Work