Audio Systems: sound card, computer sound card, fi card

Question
sir i have yamha psr 550b keyboard in which when u save the user songs in pen drive,the saved items in the pendrive cannot be played with clarity when u play it in computer why?sound card is required?what is the use of sound card?  

Answer
If you mean the computer sound card, it is pretty much mandatory to reproduce high resolution sounds. A computer w/o one has limited resources. You can get one for relatively cheap. Look at the SoundBlaster X-fi card, it runs $100 or less. You'll be glad you did.