Why are there so many video/audio and picture formats?

This is because each provider or service is trying to capture the media market throu their media formats .They want to have big market share For example : Real player ..he is the sole owner of his media formats , source code and it is copyrighted.And no can develop a player to play real formats , coz source code is a must to develop player !Thats why only real player software can alone decode all sorts of real media formats properly ! And you can see every system connected to internet has real player installed in it !