The difference between stressed and unstressed syllables lies in the emphasis or prominence given to each syllable when speaking a word. In the word "elephant," the primary stress is on the second syllable, making it pronounced as "EL-e-phant." Unstressed syllables, weak or non-stressed, are spoken with reduced emphasis and are less prominent in speech. The first and third syllables are unstressed in the word "elephant," making them pronounced as "el-E-PHANT."