The expression et al. is an abbreviation of the Latin phrase et alia, which translates into English as "and others." It is common to see et al. when a group of people of any gender are grouped together but unnamed. To be precise, however, if all of the people designated are female, it stands for et aliae, and if they are all men, it stands for et alii. It is gender neutral to use et alia as a plural.
The expression et al. is uses when a group of people co-author or edit a piece of literary work, such as an anthology. In this case, the main author or editor who headed the project will be named, and the other authors or editors will be covered under the plural et al.