Magnetic core memory

Magnetic core memory, also known as core memory or core, is an early form of random access memory. It uses small magnetic ceramic rings, the cores, through which wires are threaded to store information via the polarity of the magnetic field they contain.

Although computer memory long ago moved to silicon chips, memory is still occasionally called "core". This is most obvious in the naming of the core dump, which refers to the contents of memory recorded at the time of a program error.