Footnotes are those text particles that appear at the bottom of the writings which provide the reader with a class of additional information that may be of great interest to the reader and that is not usually found within the text as such; what we can usually find in a footer can be information, clarifications, citations, data, comments, clarifications, notes from the writers or translators, examples, etc. This is done in a place or space that is separated from the rest of the text, a space that is usually done by a blank space or line.
The footer is part of the so-called marginal notes, which are those that are positioned at the end of a chapter or at the end of a writing; which do not belong to the text either, since they provide extra information that is thought to be relevant or necessary for the reader to better digest or absorb the information. Particularly it is used more in writings of an academic, informative, expository nature than in literary ones, however they can be found from time to time in them. It should be noted that the footer is placed or annotated with smaller letters than those used in the text in question, and sometimes it may have another type or style of letter to differentiate them from those used in the text.
Footnotes can also appear in word documents or on the internet page, which likewise appear at the bottom of each page of a given site and also contain extra information that is useful for each page for the user to read. such as email address or telephone number among others.
