What is the controlled-controlled-Fredkin gate?

What is the controlled-controlled-Fredkin gate?

The controlled-controlled-Fredkin gate, also known as the Toffoli gate, is a three-qubit quantum logic gate that performs a controlled-NOT (CNOT) operation on two target qubits based on the state of a control qubit. It is named after Edward Fredkin, who proposed the gate in 1980. The gate flips the state of the target qubits if and only if the control qubit is in the state |1⟩. It is a fundamental building block in quantum computing and is used for various applications, including reversible computing and error correction.