Atmos Energy Corporation is the largest natural gas-only distributor in the U.S., serving over 3.3 million customers across eight states primarily in the South. The company operates through two segments: distribution, which involves regulated natural gas sales, and pipeline and storage, which includes intrastate pipelines in Texas and natural gas transmission in Louisiana. Atmos Energy's competitive advantage lies in its extensive infrastructure and regulated business model, allowing for stable revenue streams and cost recovery.