A supplement is added to a regular periodical, with one issue per year 12, and one issue at the end of the year is a supplement.

A supplement is an additional supplement, such as a booklet with a temporary increase in layout due to the special needs of newspapers and periodicals, or a booklet with an increase in layout on the anniversary or when necessary.

Periodicals are divided into general periodicals and supplements. Periodicals are mainly general periodicals, and supplements are supplementary supplements.