Monogamy includes monogamy, which refers to a pairwise relationship in which each individual has only one spouse. In a relationship, two people will only maintain their relationship in their lifetime, or at any time in their lives. Monogamy is different from polygamy. Monogamy in zoology means that an animal will not mate with more than one spouse at the same time.

The first marriage period refers to the period from marriage registration to becoming a legal couple and establishing a family to giving birth to the first child. The consumption characteristics of China's first marriage are: large consumption expenditure, high consumption level, obvious surprise consumption behavior, and emphasis on fashion and fashion when buying goods.

People's common idea is to regard marriage as a major event in life. The wedding was grand and warm, consuming a lot of wedding supplies and necessities for the new family. The first marriage rate is the ratio of the number of first marriages to the number of unmarried people who can get married in a certain period (such as 1 year). In order to accurately investigate the marriage degree of the population in a certain period, it is necessary to further study the first marriage rate in the population's marriage activities.

First marriage naturally ruled out remarriage. The first marriage can only happen among unmarried people who can get married. The so-called marriageable person refers to a person who has reached the legal age of marriage and entered the circle of marriage activities. Therefore, the first marriage rate is an accurate index to examine the degree of marriage of the population.