Earpads are the accessory of on-ear headphones and full-sized headphones. It is a pad which helps us get a secure fit, and gives us a cushion for longer listening sessions. It also helps us avoid outside noise to some extent in the case of open-back headphones.
On-ear headphones, sometimes known as supra-aural headphones, are a type of listening device that sits on the ear rather than completely enclosing it like traditional full-sized headphones. On-ear headphones typically come with earpads, which provide a secure fit and help to provide comfort during extended listening sessions. They also offer some noise isolation when using open-back models, helping to isolate outside sound from interfering with your audio experience.