These peoples are obviously not part of the Celtic Realm. But for research purposes in deepening one’s understandings to know somethings about them is very useful.
The Etruscan peoples covered an area between the Tiber and Arno rivers south and west of Apennines, basically what is now parts of Italy. The Etruscans civilization dates back to around 900 BCE what is called the Villanovan period. The Villanovan culture is the earliest of the Etruscan civilization until their decline in the 4th century BCE.
The Etruscans called themselves Rasenna, we are uncertain what Rasenna linguistically means.
We are uncertain of the origins of the Etruscan peoples we have a few theories one of them is Dionysius of Halicarnassus he was a Greek historian that lived around 60 BCE to around 7 BCE he suggests they are Indigenous peoples who have always lived in Etruria that is what the lands of the Etruscans are called.