2.COS is usually the abbreviation of cosplay, and cosplay is also the abbreviation of English costume and play, so the literal meaning of coa is to play a costume, and as the name implies, it is to play a role in film and television works. So cos usually refers to "role-playing", and people who play cos usually use costumes, ornaments, props and makeup to play the role of imitating the virtual world.
It is generally believed that cos originated in America, but it is popular in Japan. Cos means role-playing a role in animation. In recent years, with the growing circle of the Second Hospital, many people have seen people walking in the street wearing strange clothes.
Some of them are like characters in a large online game, some are like characters in costume TV series, some are like characters in Japanese comics, and some are like some famous stars. This is coser. As more and more people like role-playing, a circle of communication has gradually formed, which is called cos circle.