can some explain to me how birth, death and migration rates affect the population?

Question

I have read but really do not understand it?
the factors that can affect these rates i am assuming is
urbanization
cost of raising and educating children
educational and employment opportunities for women
infant mortality rate
average age at marriage
pensions
abortions
birth control
religious beliefs
some of the affects for death is
labor shortages and increased health care burdens

any help not to good on all these science terms so i quess this why i am having a hard time understanding how they affect the population?