Chevron Corporation is an American multinational energy corporation. The second-largest direct descendant of Standard Oil, and originally known as the Standard Oil Company of California (shortened to Socal or CalSo), it is headquartered in San Ramon, California, and active in more than 180 countries. Chevron is engaged in every aspect of the oil and natural gas industries, including hydrocarbon exploration and production; refining, marketing and transport; chemicals manufacturing and sales; and power generation.