A memristor ('memory resistor') is a non-volatile electronic component that regulates the flow of electrical current in a circuit and remembers the amount of charge that has previously flowed through it. Unlike a standard resistor, its resistance changes based on the history of current applied, effectively giving it a 'memory'. This property allows memristors to store information even when power is turned off and to perform logic operations, making them ideal candidates for neuromorphic computing (mimicking the brain's synapses) and high-density storage.
The concept was theorized by Leon Chua in 1971 as the fourth fundamental circuit element (alongside the resistor, capacitor, and inductor). A physical realization was claimed by HP Labs in 2008.
While still largely in the R&D phase for mass production, memristors are being actively researched for use in 'computing-in-memory' architectures to drastically reduce the energy cost of moving data between processor and memory, a key bottleneck in modern AI hardware.