Et al. is the abbreviation for several Latin words, depending upon what the writer intends it to say:

Et alii means the writer wants to say “and others (people).”

Et alia means the writer wants to say “and other things.”

Inter alios means the writer wants to say “among others (people).”

Inter alia means the writer wants to say “among other things.”

N.B. All Latin forms and meanings are abbreviated in the same way, viz., “et al.”.