Record Label:
They manufacture, distribute and promote music from a artist that is under their label. There are 2 types:
Indie record labels are independent companies that do not have a
corporate backer.
Major labels are large corporations often owned by a parent company,
like Sony.
Taking from Wikipedia:
How do they relate to the artists and the recording companies?
Within the music industry, most recording artists have become
increasingly reliant upon record labels to broaden their consumer
base, market their albums, and be both promoted and heard on MP3,
radio, and television, with publicists that assist performers in
positive media reports to market their merchandise, and make it
available via stores and other media outlets
What exactly is the function of a record label and What are they?
Within the music industry, most recording artists have become
increasingly reliant upon record labels to broaden their consumer
base, market their albums, and be both promoted and heard on MP3,
radio, and television, with publicists that assist performers in
positive media reports to market their merchandise, and make it
available via stores and other media outlets
Hope this helps!