Length-wise, trunks are between a boxer and a boxer brief. Most of the time, these underwear are made from cotton, with a spandex/polyester waistband. As boxers typically aren’t great at wicking sweat, trunks can be a better choice for exercise, as they are more absorbent while having shorter leg holes for improved mobility.
At the same time, trunks are rectangle-shaped, in contrast to the diamond-shaped brief. This means that they’re all less-constricting if you’re looking for a comfier fit. This might make them less supportive, as well.