Words have a history. They tell us about our past.
Or, at least, they tell us about the history of those who used the language. Clues to where they lived and what they thought are littered throughout their vocabulary. In English, a great example is the difference we make between pig, cow and deer in contrast to pork, beef and venison.
Words like pig, cow and deer are Anglo-Saxon, used by the inhabitants of England before the arrival of the Normans. The Norman invaders brought with them their new, posh French words and so porc (pork) and boeuf (beef) entered our vocabulary.