Magnetic Core Memory is an early form of computer memory that uses tiny magnetic rings, called cores, to store data. Each core represents a single bit of information, either a 0 or a 1, depending on the direction of the magnetic field. This technology was widely used in computers from the 1950s to the 1970s due to its reliability and speed. The cores are threaded with wires, allowing them to be magnetized and read without needing power to maintain the data. Magnetic Core Memory was eventually replaced by more advanced technologies, such as semiconductor memory, but it played a crucial role in the development of early computing systems.