WMV files are a type of video file (usually containing audio) from Microsoft. These files can be played on a variety of video players on both Mac and PC machines. Some WMV files may have digital rights management (DRM) protection which prevents users from making unauthorized copies of files purchased in online stores.
Windows Media Video (WMV) is a compressed video file format for several proprietary codecs developed by Microsoft. These files are based on the Microsoft Advanced Systems Format (ASF) container format encoded using the Windows Media Video (WMV) codec.
MPlayer Microsoft Windows Media Player PowerDVD RealPlayer VideoLAN VLC Media Player
MP3 is a digital music format which allows CD tracks to be reduced to around a tenth of their normal size without a significant loss of quality. MP3 gets rid of a lot of the information recorded in a song that our ears are not able to hear and then uses complex algorithms to reduce the file size. This then enables you to get hundreds of songs on to a CD and it also has opened up a new market over the internet - the download market as download times have been significantly reduced.
The MP3 format is a lossy format. That means that an MP3 file does not contain 100% of the original audio information. Instead, MP3 files use perceptual coding. In other words, that means it removes the information that your ear doesn't notice thereby making the file smaller. The reason lossy formats are used over RAW is that RAW audio files are too large to travel over the internet at any great speed. By using lossy formats it enables even dial up users to download mp3 files at a reasonable speed. RAW file formats generally require 176,000 bytes per second compared to a lossy format which requires 17,600. The difference is massive and so are the download times.