According to the shape classification, headphones can be divided into headphones and earplugs.
Head mounted:
The biggest difference in the shape of earplugs is the size. Over Ear Wireless Headphones，The size of these types of earphones is generally much larger than that of earplugs, and they are divided into medium-sized earphones and full-sized earphones. The earmuffs of medium-sized earphones cannot completely enclose the auricle, while full-sized earphones, also known as "big earphones", can completely enclose the auricle for better sound insulation.
Earplugs:
Generally speaking, the driver unit has a small diameter and can be worn on the outer auricle or inserted into the ear canal.
Earplugs are divided into semi-in-ear and in-ear. Generally, earplugs that can be inserted into the external ear canal are called in-ear, and those worn on the outer auricle are called semi-in-ear.