Final answer:
Passive immunity refers to receiving antibodies from an external source while active immunity involves producing antibodies through one's own immune response.
Step-by-step explanation:
When an individual is given antibodies to a disease from an external source, instead of producing them through their own immune system, this is known as passive immunity. This type of immunity can be natural, such as when antibodies are passed from the mother to child through the placenta, or it can be artificial, for example, when a person is treated with antivenom or with antibodies against a specific pathogen like the rabies virus. In contrast, active immunity involves the person's own immune system responding to a pathogen or a vaccine and developing memory cells, which can either occur naturally through infection or be induced artificially through vaccination.