A NOR Gate is a digital logic gate that produces an output of true (1) only when all its inputs are false (0). It is a combination of an OR Gate and a NOT Gate, meaning it first performs the OR operation and then inverts the result. The symbol for a NOR gate typically looks like a standard OR gate with a small circle at the output, indicating the NOT operation. In digital circuits, NOR gates are fundamental building blocks used in various applications, including arithmetic operations and memory storage. They are also significant in creating more complex logic circuits, as any logical function can be implemented using just NOR gates, making them universal gates in digital electronics.