Refers to the center-west area of Japan, typically including Osaka, Kyoto, Kobe, and surrounding prefectures. Often contrasted with 関東地方 (Kanto region).
The Kansai region has major cities such as Osaka and Kyoto.
I'm going on a business trip to the Kansai region next month.
Compound of 関西 (Kansai, literally 'west of the barrier') and 地方 (region). The term historically referred to the area west of the Osaka checkpoint (逢坂関).