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"DC" is an abbreviation which is often translated as "CC", and "Washington" is a proper noun which is often translated as "Washington". Learn more about the difference between "DC" and "Washington" below.
DC(
di
-
si
)An abbreviation is the shortened form of a word or group of words (e.g., "UFO" = "unidentified flying object"; "p." = "page").
a. CC 
We used a commutator with our AC generator to create a DC current.Usamos un conmutador con nuestro generador de CA para crear una corriente de CC.
a. D. C. 
The president visited the British prime minister before returning to Washington DC.El presidente visitó al primer ministro británico antes de volver a Washington D. C.
Washington(
wa
-
shihng
-
tihn
)A proper noun refers to the name of a person, place, or thing.
1. (city)
a. Washington 
We visited the White House when we went to Washington.Visitamos la Casa Blanca cuando fuimos a Washington.
2. (state)
a. Washington 
We had lunch at Pike Place on our visit to Seattle, Washington.Almorzamos en Pike Place en nuestra visita a Seattle, Washington.