It's used in academic writing, bibliographies, and citations to indicate that there are multiple authors of a work, but only some are listed. For example:
* Smith, J., Jones, K., et al. This means that there are more than just Smith and Jones who authored the work, but the full list of authors is not included.
The abbreviation "et al." is typically used after the first two or three authors are listed.
Here are some other ways to use "et al.":
* "et alia" can be used to refer to multiple authors, but it's less common.
* "et aliae" can be used when the work is authored primarily by women.
* "et alibi" can be used when referring to multiple locations.