Refers specifically to the western part of Europe, often contrasted with 東欧 (Eastern Europe).
See also: 東欧
Western European countries are central members of the EU.
the West; the Occident; Europe
Broader cultural and geopolitical sense, often used in contrast to 東洋 (the East) or 日本. Can encompass Europe as a whole or Western civilization.
Western culture has had a great influence on Japan.
Japan's modern architecture was strongly influenced by the West.