A memristor is a type of passive two-terminal electronic component that regulates the flow of electrical current and retains memory of past voltages. It is considered the fourth fundamental circuit element, alongside resistors, capacitors, and inductors. Memristors can change their resistance based on the history of voltage applied, making them useful for memory storage and processing information. These devices have potential applications in artificial intelligence, neuromorphic computing, and data storage. By mimicking the way synapses work in the human brain, memristors can help create more efficient and powerful computing systems. Their unique properties may lead to advancements in machine learning and smart electronics.