Chevron Corporation is an American multinational energy corporation headquartered in San Ramon, California. It is one of the world's largest oil and gas companies, with operations in over 180 countries. The company is involved in every aspect of the oil and gas industry, including exploration, production, refining, marketing, and transportation. Chevron's primary business segments include upstream, downstream, and chemicals. The upstream segment is responsible for exploration and production of oil and gas, while the downstream segment is responsible for refining, marketing, and transportation of petroleum products. The chemicals segment produces and markets petrochemicals, plastics, and other specialty products. Chevron is committed to sustainable energy and has invested in renewable energy sources such as wind and solar power. The company has a strong focus on safety, environmental stewardship, and social responsibility.