I don't have direct access to external websites to provide specific URLs, but I can certainly provide a list of key terms and explanations for each, which you can then search for on reputable websites like the United Nations Population Division, the World Bank, or academic resources for more information.
Here are six key terms from your list along with brief explanations:
Census: A periodic official count or survey of a population that collects demographic and social data about individuals in a specific geographic area.
Crude Birth Rate: The number of live births per 1,000 people in a population in a given year, without adjusting for age or sex differences.
Crude Death Rate: The number of deaths per 1,000 people in a population in a given year, without adjusting for age or sex differences.
Total Fertility Rate: The average number of children a woman is expected to have in her lifetime, based on current birth rates.
Infant Mortality Rate: The number of deaths of infants under one year old per 1,000 live births in a given year.
Demographic Transition Model: A theoretical framework that describes the process of population change over time, typically through four stages, involving changes in birth and death rates.
You can find more detailed information about these terms and related concepts by searching for them on reliable demographic and population studies websites or in academic publications