Multimedia becomes a standard in today's computing, with personal computers or handhelds. The main problems of multimedia are: real-time processing, and big data! Processor's speed is getting faster and faster by the day, so the "real-time processing" demand is not a problem anymore. The big data is just a little problem with today's storage media. But, still a big problem for the network. So, we still need the multimedia file compression, for a smaller footprint of multimedia files.
And then, there are sooooo many standards of multimedia compression: still images, audio, and video. Image standards have no more problem. But, audio and video compression are rapidly developed. And also, everybody has various preference for the compression standard.
For audio, the popular compression is MP3. But, there's also AAC, MPEG-4 Audio, OGG and the WMA (Windows Media Audio). So, user have to use the 'multi-format' audio player for playing various music with various compression.
It also happens on video: even it worse. We have MPEG for the standards: VCD and DVD. But, both is designed for offline media, not for the networks: internet and/or network streaming. Then, everybody is developing their own standard: Apple has Quicktime (.mov), Microsoft has Windows Media (.wmv, .asf), the DivX, and Adobe has the Flash (.flv) that also become popular due to YouTube.
You need a multimedia converter software to convert from a standard to another one. You'll need audio converter for the music, or just an audio files. Video encoder is needed for video conversion. Windows' users can use MOV converter to convert Quicktime files if do not like to use the Quicktime itself.
But, today, we have the all-in-one solution. Such as, Blaze Media Pro. It support so many popular multimedia compression, and can convert across them. Even, it has video editing capability. So, you can cut your videos, easily!