Proliferation refers to the rapid increase or spread of something, often used in the context of nuclear weapons or technology. It describes how these weapons can multiply in number or how their knowledge can expand to more countries or groups, raising concerns about global security. In a broader sense, proliferation can also apply to other areas, such as the growth of technology, information, or even species in an ecosystem. Understanding proliferation helps in managing its effects, whether it involves controlling nuclear arms or addressing the spread of invasive species that threaten local biodiversity.