Simply stated, all periodicals are publications that are published periodically. Periodicals are not all the same. Periodicals are presented in different mediums, they utilize different publication processes, and they appeal to a variety of readerships. Below you will find three types of periodicals. You will also find some distinctions between what the academic community considers popular and scholarly literature.
Scholarly publications are written by scholars, for other scholars. You can find scholarly articles in library databases.
Popular Publications are those like magazines and newspapers
Trade publications are geared toward individuals working in a specific profession or trade.