Academic discussion deals with concepts and theories, hypotheses and ideas. Academic writers talk more generally about the world. On the street, you might talk about your nineteen-year old cousin Vinny from Detroit taking a job at Mac Donald's. Academic discussion might talk about changing rates of unemployment, demographic factors affecting occupation selection, or the expansion of the service industry. The choice of word for any concept is essentially arbitrary.
Words come to have meaning by how they are used by native speakers.
Animals even talk differently in different languages. In English a duck says quack quack , in Italian qua qua , in Thai gaab gaab , and in Russian krya-krya . Language mirrors the history and culture of its speakers. Dialects often incorporate words or grammatical structures of other languages. Word meanings change with time hence the need to indicate the original meaning of words when we read Shakespearean plays, written around 1600, today.