Is there a difference between them?
For one thing, The Mayans lived in Guatemala & Yucatan, while the Aztecs live in what is now Mexico City!
Secondly, While the Mayan Civilization extended from early pre-history, until modern day (Many people in the Yucatan speak the Mayan language today)...
The Aztecs, who referred to themselves as "Mexica", flourished from about the 13th Century, until they were conquered by Cortes in 1521!
their languages were completely different and coming from completely different language families.