The yellow/orange shade area is Southern California
Southern California contains the major cities of Los Angeles and San Diego and is a major hub of shipping and air travel, as well as a popular tourist destination and the center of the United States' film industry (Hollywood).
The term Southern California is sometimes used as a synonym for the Greater Los Angeles Area, but this is geographically inaccurate since it excludes the state's two southernmost counties: San Diego and Imperial. For the L.A. region, the term Southland is preferred.
See also: Inland Empire (California), northern California