Bluegrass music has its roots in the southeastern part of the United States in a region known as Appalachia. The mandolin player, Bill Monroe, is given credit for being the father of the style of country music called bluegrass. He was born in Rosine, Kentucky which is known as the bluegrass state. It is the art music of country music.
Country music is music for dancing.
This is one way you can tell bluegrass from country music. Both country and bluegrass music are played all over the world now. It is flavored by the unique country tunes for a particular region. Country music in Louisiana is different than the country music in Tennessee. For one thing, the music that inspired country music in Tennessee has its roots in the folk music of England, Ireland, and Scottland.