Sequential logic is a type of digital circuit that determines its output based on both current inputs and the history of past inputs. Unlike combinational logic, where the output depends solely on the present inputs, sequential logic incorporates memory elements, allowing it to store information. This makes it essential for applications like flip-flops, registers, and counters. In sequential logic, the behavior of the circuit is defined by a sequence of states, which can change over time. These states are typically controlled by a clock signal, ensuring that changes occur in a synchronized manner. Common examples of sequential logic circuits include finite state machines and synchronous circuits.