As per the law of the United States city are defined as the entity of the government, in which most of the powers are delegated through the state as well as the county. The city must be incorporated, and a local government which is elected through the votes of the residents of the city must be formed to provide all the services to the citizens of that city. On the other hand a town is the incorporated living community which has no government powers delegated from any corner of the state or federal government.
In a town the local services are provided by the county governments. In some of the states of the USA there are special limited powers are designated to the towns. If we start discussing the hierarchy we get to know that cities are larger than the towns and towns are larger than the villages. You also have to keep in mind that in each country the local government system is different so the official definition of a town can be different from one country to another. In a layman’s language towns are much smaller than cities in terms of size and population.