1.1 Definition of demography

Demography explores the development of population, its size and structure and changes in population. The changes relate to people's births, marriages, divorces, migration and deaths. Demography also examines the mutual interaction of these phenomena and their connection to economic and social life.

The Multilingual Demographic Dictionary defines demography as follows:
"Demography is the scientific study of human populations, primarily with respect to their size, their structure and their development."

The Multilingual Demographic Dictionary contains the key concepts used in demography and the related definitions. The dictionary was prepared in co-operation with the International Union for the Scientific Study of Population (IUSSP) and it has been published in various languages. Each concept has a code of its own so that a counterpart can be found for any Finnish concept in the publications of other countries. For example, the Finnish concept 101.1 Väestötiede with the corresponding code is 101.1 Demography in the English dictionary and 101.1 Rahvastikuteadus in the Estonian dictionary.

Some of the concepts and definitions in the dictionary may seem a bit old-fashioned now, as it was published over 40 years ago. Regardless of its age, the dictionary is still very useful and it is available in well-equipped libraries - such as Statistics Finland's Library of Statistics.