While full-size around-ear or over-ear headphones seem to offer the best sound, not everyone wants to walk around wearing bulky headphones with bigger ear pads covering their ear fully. Although headphones that rest on top of one's ears are not everyone's business, on-ear versions with smaller earcups are more lightweight, travel-friendly. They have also evolved, with more versions offering aggressive noise cancellation/ noise isolation, voice assistants and other innovative technologies that have been discovered only once in larger over-ear models.
Difference between On-Ear & Around-Ear Headphones
On-ear headphones' ear pads rest on the outer ear (on the upper & lower ear lobe); over-the-ear models' have larger ear pads that encircle the ears. It is difference in the ergonomic design. On-ear headphones occupies less space & a snug fit on the ear. Over-the-ear headphones sound more spacious and expansive than on-ear headphones being wider & bigger in size covering the ear entirely inside the ear cushion.