Biological defense refers to the mechanisms and measures taken by an organism to protect itself from harmful pathogens. There are several synonyms for biological defense, including immunological defense, immune system defense, and disease resistance. Other terms include antimicrobial defense, microbiological defense, and biological warfare defense. All of these terms refer to the complex and intricate systems that organisms have developed to protect themselves from dangerous pathogens such as bacteria, viruses, fungi, and parasites. Whether through the production of antibodies, white blood cells, or other protective measures, these defenses are crucial to maintaining health and survival in a world filled with dangerous pathogens.