Area codes bring a call to the larger geographic region which may contain multiple towns; at the same time, large cities generally have multiple area codes.
Area codes came into use during the early 1940s. NPA codes were developed by AT &T and the Bell System to divide the coverage area into "number plan areas" (abbreviated NPA). NPA codes are more commonly referred to as area codes.
While the system was developed in the 40s, direct dialing of long distance did not begin until the early 50s. Some area codes are reserved for special purposes.
There are two basic types of area codes: Local and Toll Free. Toll free area codes are 800, 844, 855, 866, 877, and 888; local area codes are all the other ones.
Then of course, there is the 900 area code which represents a “toll” number, or “pay-per-call”, which many of us remember as the rather conspicuous area code.
The phone code prefix for United States is 1. There are also 505,000,000 internet hosts in the country. Approximately 245,000,000 internet users reside in United States. United States phone lines include 310,000,000 mobile phones. There are 139,000,000 landline phones in United States as well.