Let’s start with chapter Demography, this chapter is belong to the branch statistics, so let’s begin with the very first module that is introduction to demography and vital statistics, yes we would first will very much interested to know what does demography mean, demography comes from two greek words the first one is demos the meaning of this word is people and the next word is graphos now meaning of this word in greek is to measure, draw or to right something about people, so what does demography mean, so demography mean to write or measure something about people, so what is that something which we are measuring about people in demography, yes when I have a group of individuals what would I like to know about that group, what would I like to know about those people, I will like know the size, size of the group, that is size of my population next once I know the size I would like to interested to know the composition of my group now composition means sex distribution or the male female ratio in my population knowing the size, composition I would like to know the structure of the population by structure I mean age wise distribution in my population that is how many people belong to school going kids how many belong to adult group, how many belong to senior citizen group and so on lastly I would also like to measure the dynamics of my population by dynamics we mean the distribution in my population based on other parameters like income, location, etc and so on. So in demography these are the various aspects which we are going to measure about our population now the question arises how are we going to measure this yes we need to measure this by measuring the various aspects in the life of people, in the life of individual lot many events or lot many milestones occur once we start measure those milestones we will be able measure various aspects of demography ok so let’s see the various aspect in the life of individual, the first one being birth yes definitely first we are born that’s were our life begins and last one being death yes once we are born we definitely have to die but in between birth and death there are lot many events happens in our life one of them being marriage and sometimes unforcing events happen and we under go through divorce the other aspect that is very important in the life of individual that is migration yes people do migrate right, for career, for health reasons, to various countries to various cities, so these are the five very important event in the life of an individual and they are called as vital events. We measure these events that is we collect statistical information about these events and that statistical information is called vital statistics. So when we are able to measure the vital statistics then we are able measure the various aspects of our demography or population which is size, structure, composition and so on now once we know what are vital events what is vital statistics lets go ahead and look at what are the uses of these vital events, let’s look at them, the very first vital event was birth, how to do you measure or how do you record birth we have a very important document called birth certificate that is how we measure or record birth now how is this document used how does what is it let you, it tell us the date of birth, the place of birth, the citizenship of person born right similarly death is also recorded with help of death certificate this certificate has a lot of legal importance, it helps you to claim the payments from insurance companies, it is also important to claim pension benefits, it is also important to distribute property among relatives once the person dies, so these are the legal uses of death certificate, similarly we can record marriage with help of marriage certificate this certificate also has legal importance now this certificate proves your right to family pension benefits and also your right to job benefits apart from these three vital statistics are used in businesses now how do businesses use vital statistics they decide the nature of business type of business location of business based on vital statistics, vital statistics are also used in life tables what are these tables, these tables are based on mortality rates, mortality rate means death rate and they are used by insurance companies, insurance companies used these tables to decide the premiums of various insurance schemes these being very important uses of vital statistics, let’s look at last but not the least that is welfare activities how vital statistics used in welfare activities yes government various social organizations they use vital statistics to decide social security schemes for senior citizens, welfare schemes for children for kids for women for infants and so on. So these are the very important uses of vital statistics. In this chapter we saw how demography is measured that is size, structure, composition are measure with the help of vital statistics.