In the southeast the range is bounded by the Italian Padan Plain.
In the west, the valley of the Rhone river separates it from the Massif Central.
The northernmost part of the Western Alps - in the wide meaning of the term - is formed by the Swiss Prealps Sub-Range.
The peaks and mountain passes are higher compared to the Eastern Alps, while the range itself is not so broad and more arched.
In the Partizione delle Alpi (in English literally Partition of the Alps), adopted by the Italian Comitato Geografico Nazionale (National Geographic Committee) in 1926 following the IX Congresso Geografico Italiano (Italian Geographic Congress), the Alpine Range is divided into three main parts: Western, Central and Eastern Alps.