What is FOLK?
If we compare the country music of America as the lyrical, lyrical of Vietnam, Folk is almost the precursor of country. Folk is a folk song in the US in particular and the world in general. (Some folk genres are also called World Music)
Folk belongs to traditional music.
Out of old stories, from people who only know the horn without knowing anything about music, melodies, Folk has long existed in previous generations, and developed to this day.
Folk music is played with individual instruments, depending on culture, temperament and mythological. There are instruments that produce very specific sounds, when heard is known of any culture. For example, the sound from Banjo is very Far Western.
Folk music is usually played in small spaces, with few audiences. Folk music is like Vietnamese folk music, nobody plays it in the big stadium.
In America there is a legend of this genre, which is Bob Dylan