A folk ballad was written anonymously and passed down through generations before being written. Literary ballads are written to mimic the format of a folk ballad. Think Rape of the Lock (mock epic) versus Beowulf (true epic).
A ballad is any light, simple song, esp. one of sentimental or romantic character, having two or more stanzas all sung to the same melody. A poem is a composition in verse, esp. one that is...
A ballad is usually a mournful long narrative poem on the other hand an epic is a poem usually written in honor of a hero or concerning historical topics.
A literary ballad is a poem that tells a story. A tradition ballad has 2, 4, 6, 8 or 12 lines in a verse. A ballad should have a clear story. Ballads usually have tragic endings.