The term "et al." is the shortened form of the Latin term "et alia," and means "and others." The term is generally used to indicate that there are other people or things in a list that are not named, and it works similarly to "etc."
"Et al." is typically used as a space saver in situations where it would be impractical to list every person involved by name. In legal documents, the term is only used when all members are being impacted identically, such as 12 people buying equal shares of a parcel of land. Although "etc." is used similarly to "et al.," "etc." should never be used to refer to people.