Tunneling magnetoresistance (TMR) is a quantum mechanical effect observed in magnetic materials. It occurs when an electrical current passes through a thin insulating layer between two ferromagnetic materials. The resistance of the device changes depending on the relative alignment of the magnetic moments in the ferromagnets, leading to higher or lower resistance. TMR is utilized in various applications, particularly in magnetic random access memory (MRAM) and spintronic devices. These technologies leverage the unique properties of TMR to improve data storage and processing efficiency, making them promising for future electronic devices.