Population Types

 
The population can be divided into Idle Citizens, Laborers, Construction Workers, the actual number of people within the city, and the maximum possible population. 

City's Population: The city's current population.

Laborers: They are needed to work on resource production sites in the outer city. 

Construction Workers: They are required for the construction of buildings within the city.

Idle Citizens: The remaining population who can not be classified as Laborers or Construction Workers.

Maximum Population: The highest possible population your city can have based on the amount and level of your Houses.

Increasing the number of Laborers or Construction Workers will reduce the number of Idle Citizens in your city. If your activities demand more people than the city's current population, the number of Idle Citizens will become negative which will lead to reduced productivity and a decline in resource production. To remedy this problem you should upgrade your current Houses as well as building more new ones.