The file extension 3GP is a multimedia container format that is defined by 3GPP and is used on 3G mobile phones. However, it can also be used for some of the 4G and 2G mobile phones. The 3GP files store video streams as MPEG-4 part 2 or MPEG-4 part 10 (h. 264) or h. 263, and also audio streams. 3GP is a simplified version of the MP4 format and was designed to make file sizes smaller so mobile phones could support it. 3GP is able to store and transmit important priority of bytes. These files carry the description of the size of the image.
There are two formats for 3GP extensions. 3GPP is for GSM phones and the files have the 3GP extension. 3GPP2 is for CDMA mobile phones and have 3G2 extension. 3GPP and 3GPP2 are based on the MPEG-4 standards, h. 263 video format and AMR and AAC audio formats.
The MP4 file extension means compressed video files and has become famous, because it can save videos on portable devices such as MP3 players. Because it is small in size, MP4 is a good format for video-sharing sites like YouTube and Google video. It is a pity that not all programs can read MP4. There are some editing software and media players, which can not run MP4 videos directly. In such cases, you must convert them to more standard MPG files. There are many video converters available on Internet for you to convert them.
The biggest difference between 3GP and MP4 is that 3GP is for run video files on mobile phones but MP4 is for files on portable media devices and players.