There are many audio formats (or codecs) available right now. These are some popular ones.
MP3
This is the most popular, or at least, the most universal format. Every digital audio player worth its salt supports MP3, and every popular audio playback software supports MP3 playback. MP3 is plagued by patent and licensing issues, and as such, the LAME MP3 encoder is only officially distributed in source form.
MP3 is best listened at 96 to 128kbps, and is considered ‘transparent’ at 128kbps or higher. The LAME MP3 Encoder offers the best quality MP3 files.
Ogg Vorbis
Technically, .ogg files are Vorbis-encoded audio in an Ogg container, and are called Ogg Vorbis. Vorbis is an open-source codec, making it ideal as a replacement to MP3. Vorbis offers better quality at lower bitrates. However, DAPs supporting the Ogg Vorbis format is still limited.
AAC
Advanced Audio Coding is an MPEG standard and successor to MP3. It uses proprietory technology, and requires a patent license for codec development. AAC is used extensively by Apple iTunes and iTunes Store, and is supported by Apple iPods. AAC offers better quality than MP3 at lower bitrates. Support for AAC on non-Apple DAPs is limited.
WMA
Windows Media Audio is a proprietory audio compression format developed by Microsoft. WMA comes in several formats: WMA Standard, WMA Pro, WMA Lossless and WMA Voice. When the acronym “WMA” is used, it generally refers to WMA Standard. WMA offers better quality than MP3 at low bitrates. WMA enjoys better support on DAPs.
Conclusion
There is, of course, no audio format that is the best. It depends on your needs. MP3 is the lowest common denominator, and has the widest support. If you own an iPod or two, and you do not intend to switch, then AAC is the natural choice. Likewise, if you have no intention to switch to Apple DAPs, and smaller audio files are important, you might consider WMA. And finally, if open source and quality is important, and you do not mind the limited DAP support, then go for Ogg Vorbis.
