Charleston is the most populous city in the U.S. state of South Carolina, the county seat of Charleston County, and the principal city in the Charleston metropolitan area. The city lies just south of the geographical midpoint of South Carolina's coastline on Charleston Harbor, an inlet of the Atlantic Ocean formed by the confluence of the Ashley, Cooper, and Wando rivers. Charleston had a population of 150,227 at the 2020 census. The population of the Charleston metropolitan area, comprising Berkeley, Charleston, and Dorchester counties, was estimated to be 849,417 in 2023. It ranks as the third-most populous metropolitan statistical area in the state, and the 71st-most populous in the United States.

Columbia is the capital city of the U.S. state of South Carolina. With a population of 136,632 at the 2020 census, it is the second-most populous city in South Carolina. The city serves as the county seat of Richland County, and a portion of the city extends into neighboring Lexington County. It is the center of the Columbia, SC Metropolitan Statistical Area, which had an estimated population of 858,302 in 2023, and is the 70th-most populous metropolitan statistical area in the United States. The name Columbia is a poetic term used for the United States, derived from the name of Christopher Columbus, who explored for the Spanish Crown. Columbia is often abbreviated as Cola, leading to its nickname as "Soda City".