Urbanization means the movement of population from rural areas(villages) to urban areas (cities and towns). The main reasons for urbanization are employment, people move to cities in the hope of job opportunities as there are less opportunities left in the agricultural sector which is the main occupation of the people living in the villages. People also move to cities for better education as there are less schools in villages and hardly any prohibition for higher education. Educated population of the rural areas urge for better standard of living as cities provide better public services to people. You can also say that urbanization is the way to development.