Nature vs. Nurture
Nature and nurture are often compared when exploring influences on human or animal behavior. Nature is considered to be the innate qualities passed on through genetics, while nurture refers to experiences (how someone is raised, education, etc.). It is widely accepted by scientists that both nature and nurture influence development.
In this context, nature refers to an individual's innate qualities. Nature does not change based on external factors. For example, a person with genes for curly hair will have curly hair no matter where he or she is born and how they are raised.
Nurture refers to personal experience. Nurture does change based on external factors. For example, a person with genes for being tall could possibly have their growth stunted due to malnutrition.
Nature and nurture are often studied by examining the lives of twins (who are similar in nature, or genetics) who were raised apart (differing nurture).