The size S (small) is usually suitable for people who are thin, and its English translation is "small" and its abbreviation is S.
SM code (middle code) is usually suitable for people with ordinary figure. Its English translation is "middle" and can be abbreviated as M.
However, this is only the size definition of some brands or clothing types, and the specific situation may be different due to different brands and clothing types. For example, in some brands or clothing types, SM code may be equivalent to S code in other brands or clothing types. Therefore, when buying or choosing a size, it is best to choose a size that suits you according to a specific brand or clothing type.