Durham is a city in the U.S. state of North Carolina. It is the county seat of Durham CountyIn 2003, the previous Raleigh-Durham-Chapel Hill metropolitan statistical area (MSA) was re-defined by the U.S. Office of Management and Budget, resulting in the formation of the Raleigh-Cary, NC MSA and the Durham, NC MSA.Durham is the core of the four-county Durham-Chapel Hill MSA, which has a population of 504,357 as of Census 2010. The US Office of Management and Budget also includes Durham as a part of the Raleigh-Durham-Cary Combined Statistical Area, which has a population of 1,749,525 as of Census 2010. Effective June 6, 2003 the Office of Management and Budget redefined the Federal Statistical Areas and dismantled what had been for decades the Raleigh-Durham-Chapel Hill, MSA and split them into two separate MSAs even though the region still functions as a single metropolitan area.