A memristor is a device that behaves as an electrical resistance switch that can retain a state of internal resistance based on history of applied voltage and current. The memristor can store and process information, and offers several performance characteristics that exceed that of conventional integrated circuit technology. An important class of memristive device is a two-terminal resistance switch based on ionic motion, which is built from a simple conductor-insulator-conductor thin-film stack. For large scale applications, the memristor device can be used in the form of crossbar array.