Here is a layout of Charlotte Douglas International Airport. CLT currently has four Runways:
23/5 is currently not in use, and only open every now and then. Its mostly a taxiway to relief the cramped apron areas.
18L / 36C is the Eastern most runway. This is typically used for Arrivals and Departures to the East, like Boston, New York, Washington as well as Miami, Fort Lauderdale and others.
18C / 36C is the Center runway and is used mostly for departures to the West. There are only a few flights that arrive here
18R / 36L is the Western most runway and is only used for arrivals from the West.