A marginal note is a brief comment or observation written in the margin of a book, document, or manuscript. There are several synonyms for the term that can be used interchangeably, such as footnote, annotation, jotting, notation, remark, and commentary. A footnote is a piece of additional information, usually placed at the bottom of a page, that provides clarification or citation. An annotation is a brief note or comment added to a text, especially for explanatory purposes. Jotting and notation both refer to a brief written record or reminder. A remark is a comment or opinion expressed about something. Lastly, a commentary is a systematic analysis or explanation, usually written in a scholarly or critical manner.