The term "traditional folk" (or "traditional music") is often used interchangeably with "folk music". Apart from instrumental music that forms a part of traditional music, especially dance music traditions, much traditional music is vocal music, since the instrument that makes such music is usually handy. As such, most traditional music has meaningful lyrics.
Before artists like Bob Dylan, the Kingston Trio, and the Weavers popularized folk among hip young college kids, the music existed in many forms in the U.S.--rural old-time songs passed from family to family (and generation to generation), broadly political or satirical songs, children's tunes, minstrel songs. This is a catch-all category for traditional folk music before it became the voice of the Sixties.