A : audio files with *.ogg extension are Ogg Vorbis compressed audio format from free softwares. As mp3, wich is not free, it gives lighter files to be share on the web, instead of wav files that are not compressed and not free.
If you are using GNU/Linux it's easy, all free players are able to play free formats. If you're still using Windows I found 3 possibilities :
Installing Ogg codecs for
Windows Media Player :
Download Ogg Codecs : http://www.illiminable.com/ogg/oggcodecs_0.71.0946.exe
Uninstall previous Ogg Codecs. (This is really important!).
Close all media applications.
Start the installer.
logo is your friends. It's about syndication (syndication : http://en.wikipedia.org/wiki/RSS ). Click on the RSS icon and save the content in your aggregator your web navigator Firefox or your email client messenger Thunderbird.