They had many differences. The Aztecs lived in central Mexico. Often, “Aztec” is used to refer to people who lived in Tenochtitlan, which is now Mexico City, on an island in Lake Texcoco, but may also refer to their allies, the Acolhuas of Texcoco and the Tepanecs of Tlacopan. The Maya people spread from southern Mexico, through to Guatemala, Belize, western Honduras and northern El Salvador. The Aztecs created a large empire across Mexico through tribute and trade. They built many pyramids, some of which still stand today. The Mayas had the only known fully developed written language in pre-Columbian America. Their most notable monuments are the stepped pyramids and the palaces built for Maya rulers.