Antiballistic missile is often abbreviated as ABM. Synonyms for this term include anti-missile missile (AMM), anti-missile defense system (AMDS), missile defense system (MDS), ballistic missile defense (BMD) and missile shield. These terms refer to the military technology that is designed to intercept and destroy incoming ballistic missiles. Many countries are investing in the development of ABM technology to enhance their national security. Recent advancements in ABM technology have made it possible for missiles to be intercepted in outer space, resulting in increased defense capabilities. These synonyms are often used interchangeably depending on the context of discussion.