678 is a telephone area code assigned to metropolitan Atlanta, Georgia and its suburbs and exurbs. This area code was first assigned to customers signing up for new telephone service on January 15, 1998. The telephone or phone (Greek: tele = far away and phone = voice) is a telecommunications device which is used to transmit and receive sound (most commonly voice and speech) across distance. ... A telephone numbering plan is a system that allows subscribers to make and receive telephone calls across long distances. ... According to the 2000 census, the 28-county Atlanta, Georgia metropolitan area has a population of 4,247,981 making it the eleventh largest metropolitan area in the United States. ... Illustration of the backyards of a surburban neighbourhood Suburbs are inhabited districts located either on the outer rim of a city or outside the official limits of a city (the term varies from country to country), or the outer elements of a conurbation. ... The expression exurb (for extra-urban) was coined in the 1950s to describe the ring of prosperous rural communities beyond the suburbs that, due to availability via the new high-speed limited-access highways, were becoming dormitory communities for an urban area. ... January 15 is the 15th day of the year in the Gregorian calendar. ... 1998 (MCMXCVIII in Roman) is a common year starting on Thursday of the Gregorian calendar, and was designated the International Year of the Ocean. ...

It is generally reserved for use outside the northern half of Interstate 285, serving Atlanta's booming northern suburbs of Marietta, Alpharetta, and Cumming with 404 generally reserved for inside the Perimeter(I-285). INTERSTATE JUNCTIONS JUNCTION EXIT # Interstate 20 10 Interstate 75 20 Georgia 400 27 Interstate 85 33 U.S. 78 39 Interstate 20 46 Interstate 675 52 Interstate 75 58 Interstate 85 61 Legend BROWSE STATE HWYS Prev Next GA-406 GA-408 Interstate 285 (abbreviated I-285) is a beltway... Marietta is a city located in central Cobb County, Georgia6, and is its county seat. ... Alpharetta is a city located in Fulton County, Georgia. ... Cumming is a city located in Forsyth County, Georgia. ... Area code 404 covers Atlanta and its immediate neighbors, roughly within Interstate 285. ... Interstate 285 (Georgia State Route 407), usually known as the Perimeter, is a beltway interstate highway encircling Atlanta, Georgia for 64 miles (103km). ...

This area code also serves north Georgia and is an overlay with the 404, and 770 area codes. Area code 404 covers Atlanta and its immediate neighbors, roughly within Interstate 285. ...

Currently, cell phone subscribers can choose from either the 404, 678, or 770 area code when signing up for service. In shorthand, it is usually written as 6/555-1234.