Magkaiba. First, normally you would want the song to be shorter (edited down) so that radio programmers would want to program your songs as part of their play list. Second, the sound has to be bigger, more compressed but with appreciable dynamics so it stands out from everybody else - much like what the US or foreign made records exhibit as characteristic. In the olden days where singles or 45 rpm records were the norm as promotional copies for radio stations, one side is the radio edit, the other side is the commercial or album version. The radio edit is the one played for on air. Nowadays, as most promotional copies are from the commercial CDs themselves, the practice of coming out with the radio version is not done as much. But still, the radio version will stand out if done by artists or by record labels.
FWIW