California is a place.
California ( [ kælᵻˈfɔːrnjə , _ - ni.ə ] , ) is the most populous state in the United States and the third most extensive by area . Located on the western ( Pacific Ocean ) coast of the U.S. , California is bordered by the other U.S. states of Oregon , Nevada , and Arizona and shares an international border with the Mexican state of Baja California . California also has the nation 's most populous county , Los Angeles County , and its largest county by area , San Bernardino County . Though California is well-known for its warm Mediterranean climate , the large size of the state means it can vary from moist temperate rainforest in the north , to arid desert in the interior , as well as snowy alpine in the mountains . California is a place name used by three North American states : in the United States by the state of California , and in Mexico by the states of Baja California and Baja California Sur .