According to Wikipedia, urbanization can be defined as the population shift from rural to urban areas, the corresponding decrease in the proportion of people living in rural areas, and the ways in which societies adapt to this change.

Urbanization in Nigeria refers to the share of urban population in the total population of the country. In 2022, the Nigerian population was approximately 218,540,000, the urban population was 53.52% of the total population which was approximately 116,960,000. A country's urbanization rate refers to the share of the total population living in an urban setting. 

Urbanization has helped Nigeria in many ways such as

1. More education and employment opportunities: Urbanization has helped to educate more citizens by allowing them to attend proper schools. It has also helped to provide employment opportunities for these educated citizens.

2. Increased quality of life: When more citizens are able to do their jobs, this helps to generate more revenue for the government which leads to reduced cost of living which in turn leads to an improved quality of living.

3. Better access to healthcare: People are able to receive better healthcare.

Disadvantages of Urbanization.

1. Dense Population: The more people move to urban areas, the denser they become.

2. Higher cost of houses: As more people move to urban areas, there is a higher demand for houses which in turn increases the prices.

3. Fewer green spaces: The denser the areas get, the less green they are.