Core memory operates by using small magnetic cores made of a ferromagnetic material such as ferrite, which are woven together into a grid of wires. Each core represents one bit of data, and the state of the core can be magnetized to represent either a 0 or a 1.
To read or write data to core memory, an electrical pulse is sent through the wires that intersect at the desired core, which causes the magnetic field of the core to either change or remain the same. The state of the core is then detected and interpreted as a 0 or 1.
Core memory was a reliable and relatively fast form of memory for its time, but it was eventually superseded by semiconductor-based memory technologies, such as dynamic random-access memory (DRAM), which were smaller, faster, and more energy-efficient.