Simplify the following text for a Grade 10 native English-speaking person.
Original: The Iroquois , also known as the Haudenosaunee or the `` People of the Longhouse '' , are an association of several tribes of indigenous people of North America .
Simplified: The Iroquois , also known as the Haudenosaunee or the `` People of the Longhouse '' , are a group of several tribes of indigenous people of North America .