The document discusses biological warfare and biological weapons. It defines biological warfare as using biological agents like bacteria, viruses, and fungi to harm or kill humans, animals, and plants. It provides examples of historical uses of biological weapons and diseases used in warfare like anthrax and glanders. The document outlines the development of biological weapons by nations in the 20th century and bans on their use through treaties. However, it notes that some countries still maintain secret biological weapons programs today in violation of treaties.