If you write and record your own songs, then you’re both a Composer and a Recording Artist. But that’s not always the case.
For example, Leonard Cohen wrote the composition “Hallelujah” but there are lots of different sound recordings of that song.
By Leonard Cohen himself, who is also a recording artist for that song.
By other recording artists like Jeff Buckley, John Cale and k.d. lang.
Songwriters and Recording Artists are not represented by the same people….
Music Publishers will try to maximize the number of times the Composition is performed (on TV, on the radio, live, etc).
Because every time the composition is performed, the Composer and the Publisher get paid.
Record Companies will try to maximize the number of times the Sound Recording is copied (on an CD, vinyl, DVD, video game).
Because that’s when the Recording Artist and Record Company get paid.