Well....thats good question. Mp3 is a universal audio format which is almost compatible with all media players whereas mp4 is video format in compressed mode which is specially designed for some selected players like mobile phones and playstations.

Answered by Madhu Jain , an ibibo Citizen, at 9:42 AM on April 27, 2008

Well.....mp3 is audio format compatible with almost all media players and mp4 is a special video format which is compressed in mode which is only compatible with some selected media players. mp4 files are specially designed for mobiles phones and playstations and are epl. high resolution vidoes.

Answered by Samrat , an ibibo Advisor, at 6:54 PM on April 26, 2008

MP3 is an MPEG standard used especially for digitally transmitting music over the Internet.
A file containing a song or other audio data that is encoded using this standard: The band released its latest single as an MP3 on the Internet.

MP4 refers to: MPEG-4 Part or *.mp4, is a file format (a so called container) specified as a part of the ISO/IEC MPEG-4 international standard. It is used to store media types defined by the ISO/IEC Moving Picture Experts Group, and can be used to store other media types as well. It is, or will be, typically used to store data in files, though it will be used in data streams and possibly in other ways.

Answered by Ashu Kumar , an ibibo Citizen, at 10:21 PM on April 25, 2008

Well Jeet , MP3 and MP4 differs in a big way.

In one hand , MPEG-1 Audio Layer 3, more commonly referred to as MP3, is a digital audio encoding format using a form of lossy data compression.

It is a common audio format for consumer audio storage, as well as a de facto standard encoding for the transfer and playback of music on digital audio players.

MP3's use of a lossy compression algorithm is designed to greatly reduce the amount of data required to represent the audio recording and still sound like a faithful reproduction of the original uncompressed audio for most listeners, but is not considered high fidelity audio by most audiophiles.

An MP3 file that is created using the mid-range bitrate setting of 128 kbit/s will result in a file that is typically about 1/10th the size of the CD file created from the original audio source. An MP3 file can also be constructed at higher or lower bitrates, with higher or lower resulting quality.

Where as , MP4 MPEG-4 is a multimedia container format standard specified as a part of MPEG-4. It is most commonly used to store digital audio and digital video streams, especially those defined by MPEG, but can also be used to store other data such as subtitles and still images.

Like most modern container formats, MPEG-4 Part 14 allows streaming over the Internet. The official filename extension for MPEG-4 Part 14 files is .mp4, thus the container format is often referred to simply as MP4.

For more details , Please visit the source sites :

1) http://en.wikipedia.org/wiki/M P3

2) http://en.wikipedia.org/wiki/M PEG-4_Part_14

Answered by Alok Gupta , an ibibo Guru, at 7:58 PM on April 25, 2008