Folk is a music genre that focuses more on a style of music rather than a composition structure. Folk artists tend to focus on songs about war protest, environmentalism, compassion, and justice. Because folk singers tend to travel to various demonstrations, the choice of instrument is often the guitar since it's highly portable. It's common for folk music to have strong rock undertones, and when it does, it is referred to as folk rock.
- en.wikipedia.org/wiki/Folk_music - Wikipedia.