Quantum measurement is a research area within quantum mechanics that focuses on the process of measuring quantum systems, which are entities such as atoms, photons, or electrons that exhibit quantum behavior. This includes studying how quantum systems interact with measuring devices, how quantum information is extracted from these systems, and how measurement affects the state of the system. Quantum measurement is a fundamental aspect of quantum mechanics and plays a crucial role in understanding the behavior of quantum systems and their applications in fields such as quantum computing and quantum communication.