Exotic matter is a theoretical type of matter that has unusual properties, such as negative mass or negative energy density. Unlike ordinary matter, which has positive mass and energy, exotic matter could potentially allow for phenomena like faster-than-light travel or stable wormholes, as suggested by some interpretations of general relativity. Scientists have not yet discovered exotic matter in nature, and its existence remains speculative. Research in quantum physics and cosmology continues to explore the implications of exotic matter, particularly in relation to black holes and the expansion of the universe.