The administration of a city is generally headed by a mayor or municipal president and / or a council, all elected by popular vote (in democratic regimes). He is usually in charge of looking after the interests of his fellow citizens, representing them before the higher hierarchical authority, in addition to promoting local policies to improve their quality of life, such as health or sports programs, and fighting crime, among other various tasks. Its budget generally comes from national funds and certain own income, such as trade permits, building or specific taxes.
Currently, the economy of cities is general and highly diversified, varying between cities. Since the urban economy is never based solely on a certain economic sector, several cities depend mainly on a single, or a few, economic sectors. Some cities, however, still rely heavily on agriculture and ranching, such as Saskatoon. The economy of large cities tends to be more diversified, but this does not always happen. In larger cities, the manufacturing industry is almost always one of the main sources of income, generating thousands of jobs, although industry is no longer the largest economic activity in cities, transferring this position to the services sector. In several large cities, thousands of people work daily in offices and financial institutions. Cities such as New York, Tokyo, London, Paris and Hong Kong are major financial centers, where this activity is the main source of income for the city. In other cities, such as Rome, Quebec and Foz do Iguazú, they depend heavily on tourism. Several cities have a highly diversified economy, that is, where all sectors have approximately the same importance, so they are less vulnerable to economic recessions compared to those cities that depend on a particular economic sector.
A metropolis is a large population center, consisting of a large central city (sometimes two or more) and its adjacent area of influence, made up of other smaller and relatively close cities and / or localities. Generally, metropolises form conurbations, forming a single urban area. For example, Mexico City is a central city, and with Naucalpan, Ecatepec de Morelos, Tultitlán and other adjacent towns together they form a conurbation, known as the “Metropolitan Zone of Mexico City.”
However, a metropolis does not necessarily need to be formed by a single contiguous urbanized area, and the union of two or more urbanized areas interspersed with rural areas can be designated as a metropolis.